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Background: The GM1 and GM2 gangliosidoses and type 2 Gaucher disease (GD2) are inherited lysosomal storage disorders with most cases having symptom onset in infancy and reduced life expectancy. The conditions are rare, and there is therefore a need for accurate and up to date information concerning the disease course and survival to assist in the design of clinical trials. RETRIEVE is a natural history study aiming to: (1) collect data on the survival of patients with early-onset (onset of first neurological manifestation before 24 months of age) GM1, GM2, or GD2; (2) collect data that could constitute a historical control group for future clinical trials; and (3) evaluate whether the conditions can be assessed together in a single interventional clinical trial. Group A included patients who were deceased or with unknown survival status at enrollment and was thus limited to retrospective data. Group B included patients who were alive at enrollment, who were followed prospectively with additional retrospective data collection. Results: Group A included 185 patients (60 with GM1, 78 with GM2, and 47 with GD2), and Group B included 40 patients (18 with GM1, 16 with GM2, and 6 with GD2). Mean and median age at diagnosis and age at onset of first neurological manifestation were youngest in patients with GD2 and oldest in patients with GM2 in both groups. In Group A, median (95% CI) survival was 19.0 (18.0, 22.0), 44.0 (37.0, 51.9) and 14.0 (10.0, 16.0) months in patients with GM1, GM2 and GD2, respectively. In Group B, hypotonia was experienced by most patients with GM1 (17/18, 94.4%), and was less common in patients with GM2 (12/16, 75.0%) and GD2 (4/6, 66.7%). Strabismus and splenomegaly were reported in all six patients with GD2. Conclusions: RETRIEVE is one of the largest natural history studies of GM1, GM2, and GD2. Results were generally consistent with the published literature, with differences potentially due to variation in inclusion criteria. The difference in median survival between patients with early-onset GM1, GM2, and GD2 reported in this study suggests that the three diseases should not be pooled for study in clinical trials. [ABSTRACT FROM AUTHOR]

Background: Pain is common in the genetic skin fragility disorder epidermolysis bullosa (EB), from skin and mucosal injury and inflammation as well as extra-mucocutaneous sites. Individuals living with EB have identified pain as a priority for better treatments. Objectives: The Prospective EB Longitudinal Evaluation Study (PEBLES) is a prospective register study exploring the natural history of RDEB across all ages from birth to death. Here, we investigated the characteristics and treatment of pain in different RDEB subtypes. Methods: Information was collected from individuals with different RDEB subtypes over an 8-year period. Data included visual analogue scale (VAS) ratings of background and procedural pain, its location, intensity and impact on sleep, as well as pain medication. Disease severity scores and quality of life measures were correlated to pain scores. Results: Sixty-one participants (13 children, 48 adults) completed a total of 361 reviews. Pain was common, experienced by 93% of participants at index review, with 80% suffering both background and procedural pain. Across all RDEB patients, the median VAS for background pain was 40 (out of 100) [interquartile range 20,60] and for those having regular dressing changes, median procedural pain was 52 [40,80]. Severe (RDEB-S) and pruriginosa (RDEB-Pru) groups had the greatest increase in procedural compared to background pain of 20 and 22 VAS points, respectively. Correlations between disease severity and quality of life impairment were observed across most groups, particularly RDEB-S. Over half of those studied experienced pain frequently or constantly, and in one third pain disturbed sleep at least 4 nights per week. Skin was the commonest source of pain in all subtypes except inversa RDEB where the mouth was the main site. Despite frequent and severe pain, one third of participants used no medication for pain and, in those that did, pain levels remained high suggesting ineffectiveness of current pain management approaches and a significant unmet need in RDEB. Conclusion: The frequency, severity, and impact of pain in all RDEB patients is significant, particularly in RDEB-S and RDEB-Pru. Our findings highlight that current RDEB pain management is poorly effective and that further research is needed to address this symptom. [ABSTRACT FROM AUTHOR]

Abstract Background The GM1 and GM2 gangliosidoses and type 2 Gaucher disease (GD2) are inherited lysosomal storage disorders with most cases having symptom onset in infancy and reduced life expectancy. The conditions are rare, and there is therefore a need for accurate and up to date information concerning the disease course and survival to assist in the design of clinical trials. RETRIEVE is a natural history study aiming to: (1) collect data on the survival of patients with early-onset (onset of first neurological manifestation before 24 months of age) GM1, GM2, or GD2; (2) collect data that could constitute a historical control group for future clinical trials; and (3) evaluate whether the conditions can be assessed together in a single interventional clinical trial. Group A included patients who were deceased or with unknown survival status at enrollment and was thus limited to retrospective data. Group B included patients who were alive at enrollment, who were followed prospectively with additional retrospective data collection. Results Group A included 185 patients (60 with GM1, 78 with GM2, and 47 with GD2), and Group B included 40 patients (18 with GM1, 16 with GM2, and 6 with GD2). Mean and median age at diagnosis and age at onset of first neurological manifestation were youngest in patients with GD2 and oldest in patients with GM2 in both groups. In Group A, median (95% CI) survival was 19.0 (18.0, 22.0), 44.0 (37.0, 51.9) and 14.0 (10.0, 16.0) months in patients with GM1, GM2 and GD2, respectively. In Group B, hypotonia was experienced by most patients with GM1 (17/18, 94.4%), and was less common in patients with GM2 (12/16, 75.0%) and GD2 (4/6, 66.7%). Strabismus and splenomegaly were reported in all six patients with GD2. Conclusions RETRIEVE is one of the largest natural history studies of GM1, GM2, and GD2. Results were generally consistent with the published literature, with differences potentially due to variation in inclusion criteria. The difference in median survival between patients with early-onset GM1, GM2, and GD2 reported in this study suggests that the three diseases should not be pooled for study in clinical trials.

Abstract Purpose Aicardi syndrome is a rare epileptic encephalopathy, almost exclusively affecting girls. It was first described as a triad of infantile spasms, chorioretinal defects and agenesis of the corpus callosum. The etiology remains unknown and there is uncertainty on best practice therapy and outcome. We aimed at defining quantitative clinical endpoints that will inform future research and clinical trials. Methods Quantitative natural history modeling of cases with Aicardi syndrome from published clinical reports. Main outcome measures were age at disease onset, survival and diagnostic delay. Phenotypic features of affected individuals as well as neuroradiological and ophthalmological features were descriptively stated. STROBE criteria were respected. Results Two hundred forty-five cases were available for analysis. Median age at disease onset was 2.2 months. Median diagnostic delay was 1 month. Mortality was estimated with 6% at 1 and 17% at 5 years of age. 60% of children showed the classic clinical features, while 40% met the revised diagnostic criteria. We delineate possible predictors of disease severity and of seizure control. Conclusion We provide natural history data including geographical localization of 245 published patients with Aicardi syndrome. Quantitative history modeling in rare epileptic encephalopathies will help to raise disease awareness and facilitate future clinical trials as one core element of quantitative systems pharmacology.

Abstract Background Pain is common in the genetic skin fragility disorder epidermolysis bullosa (EB), from skin and mucosal injury and inflammation as well as extra-mucocutaneous sites. Individuals living with EB have identified pain as a priority for better treatments. Objectives The Prospective EB Longitudinal Evaluation Study (PEBLES) is a prospective register study exploring the natural history of RDEB across all ages from birth to death. Here, we investigated the characteristics and treatment of pain in different RDEB subtypes. Methods Information was collected from individuals with different RDEB subtypes over an 8-year period. Data included visual analogue scale (VAS) ratings of background and procedural pain, its location, intensity and impact on sleep, as well as pain medication. Disease severity scores and quality of life measures were correlated to pain scores. Results Sixty-one participants (13 children, 48 adults) completed a total of 361 reviews. Pain was common, experienced by 93% of participants at index review, with 80% suffering both background and procedural pain. Across all RDEB patients, the median VAS for background pain was 40 (out of 100) [interquartile range 20,60] and for those having regular dressing changes, median procedural pain was 52 [40,80]. Severe (RDEB-S) and pruriginosa (RDEB-Pru) groups had the greatest increase in procedural compared to background pain of 20 and 22 VAS points, respectively. Correlations between disease severity and quality of life impairment were observed across most groups, particularly RDEB-S. Over half of those studied experienced pain frequently or constantly, and in one third pain disturbed sleep at least 4 nights per week. Skin was the commonest source of pain in all subtypes except inversa RDEB where the mouth was the main site. Despite frequent and severe pain, one third of participants used no medication for pain and, in those that did, pain levels remained high suggesting ineffectiveness of current pain management approaches and a significant unmet need in RDEB. Conclusion The frequency, severity, and impact of pain in all RDEB patients is significant, particularly in RDEB-S and RDEB-Pru. Our findings highlight that current RDEB pain management is poorly effective and that further research is needed to address this symptom.

Abstract Background An increasing number of clinical trials for new therapeutic strategies are underway or being considered for dystrophinopathy. Having detailed data on the natural progression of this condition is crucial for assessing the effectiveness of new drugs. However, there’s a lack of data regarding the long-term data on the natural course and how it’s managed in China. In this study, we offer a comprehensive overview of clinical and molecular findings, as well as treatment outcomes in the Chinese population. Methods Institutional data on all patients with dystrophinopathy from August 2011 to August 2021 were retrospectively reviewed. The data included geographic distribution, age at diagnosis, molecular findings, and treatment options, such as corticosteroids, cardiac interventions, and clinical outcomes. Results In total, 2097 patients with dystrophinopathy, including 1703 cases of Duchenne muscular dystrophy (DMD), 311 cases of Becker muscular dystrophy (BMD), 46 cases of intermediate muscular dystrophy (IMD), and 37 cases categorized as “pending” (individuals with an undetermined phenotype), were registered in the Children’s Hospital of Fudan University database for dystrophinopathy from August 2011 to August 2021. The spectrum of identified variants included exonic deletions (66.6%), exonic duplications (10.7%), nonsense variants (10.3%), splice-site variants (4.5%), small deletions (3.5%), small insertions/duplications (1.8%), and missense variants (0.9%). Four deep intronic variants and two inversion variants were identified. Regarding treatment, glucocorticoids were administered to 54.4% of DMD patients and 39.1% of IMD patients. The median age at loss of ambulation was 2.5 years later in DMD patients who received glucocorticoid treatment. Overall, one cardiac medicine at least was prescribed to 7.4% of DMD patients, 8.3% of IMD patients, and 2.6% of BMD patients. Additionally, ventilator support was required by four DMD patients. Eligibility for exon skipping therapy was found in 55.3% of DMD patients, with 12.9%, 10%, and 9.6% of these patients being eligible for skipping exons 51, 53, and 45, respectively. Conclusions This is one of the largest studies to have evaluated the natural history of dystrophinopathy in China, which is particularly conducive to the recruitment of eligible patients for clinical trials and the provision of real-world data to support drug development.

Abstract Background Malan syndrome (MALNS), previously referred to as “Sotos syndrome 2” due to its resemblance to Sotos syndrome (SS), is an ultra-rare neurodevelopmental disorder characterized by overgrowth, typical craniofacial features, intellectual disability (ID), and a range of psychobehavioral, musculoskeletal, vision and neurological signs. As MALNS and SS partly overlap, it is essential to more accurately profile their clinical presentations and highlight their differences in order to improve syndrome specific management. An increasing number of individuals with MALNS reach adult-age though the natural history of the disorder is poorly characterized due to the small number of adult individuals described so far. As a consequence, current guidelines are limited to the pediatric population. Further delineation of MALNS is essential to optimize care in adulthood. Results A mixed approach based on cross-sectional data collection with a survey disseminated to caregivers of adults with molecularly confirmed MALNS and literature review was conducted. Twenty-eight caregivers completed the survey. Clinical presentation in adulthood is multisystemic and defined by psychobehavioral comorbidities (96%), musculoskeletal involvement (96%), vision impairment (96%) and neurological complications (86%). The most common signs were anxiety (79%), hypotonia (75%), movement difficulty (75%), scoliosis (64%), problems with coordination (61%), strabismus (57%), constipation (54%), breastbone abnormalities (54%) and advanced bone age during childhood (54%). Impaired vision was complicated by vision decline (36%) and optic atrophy (32%). We report some previously unidentified features, including high pain threshold (46%), incontinence (25%), tremors (21%), muscle hypoplasia (18%) and tics (18%). Conclusions This survey in the adult population has allowed a more complete description of the natural history of MALNS. Our findings will contribute to the development and improvement of standards of care for adults with MALNS to assure optimal health monitoring and treatment of evolutive complications. We propose additional recommendations to the previous dataset of clinical evaluations specifically applied to adults. The comparison of MALNS and SS adult presentation highlights significant differences in terms of prevalence and severity of ID, behavioral issues, and vision problems, confirming that a proper differential diagnosis between the two conditions is indispensable to guide physicians and mental health professionals to syndrome specific management.

Background: Alpha-methylacyl-CoA racemase (AMACR) deficiency is a rare peroxisomal enzyme deficiency caused by biallelic variants in the AMACR gene. This deficiency leads to the accumulation of toxic bile acid intermediates (R)-trihydroxycholestenoic acid (THCA) and (R)-dihydroxycholestenoic acid (DHCA) and pristanic acid. With less than 20 patients described in literature, the phenotype of AMACR deficiency is poorly defined and no data on the natural history are available. Results: Here we describe a cohort of 12 patients (9 adults and 3 children) with genetically confirmed AMACR deficiency (median age at diagnosis 56 years, range 3–69), followed for an average of 6 years (between 2015 and 2023). Five novel pathogenic variants are described. In 5/9 adult patients, retinitis pigmentosa was detected at a median age of 45 years (range 30–61). The median delay to diagnosis of AMACR deficiency after the diagnosis of retinitis pigmentosa was 24 years (range 0–33). All adult patients subsequently developed neurological signs and symptoms after the age of 40 years; most frequently neuropathy, ataxia and cognitive decline with prior normal cognitive functioning. One patient presented with a stroke-like episode. All adult patients showed a typical MRI pattern involving the thalami and gray matter structures of the pons and midbrain. One patient had a hepatocellular carcinoma at the time of the AMACR deficiency diagnosis and two patients suffered from gallstones. All three included children had elevated liver transaminases as single presenting sign and showed no brain MRI abnormalities. Conclusion: AMACR deficiency can be considered as an adult slowly progressive disease with a predominant neurological phenotype. The main signs comprise retinitis pigmentosa, neuropathy, ataxia and cognitive decline; stroke-like episodes may occur. Recognition of typical MRI abnormalities may facilitate prompt diagnosis. In addition, there is a risk of liver fibrosis/cirrhosis and hepatocellular carcinoma in these patients, requiring active monitoring. [ABSTRACT FROM AUTHOR]

Background: An increasing number of clinical trials for new therapeutic strategies are underway or being considered for dystrophinopathy. Having detailed data on the natural progression of this condition is crucial for assessing the effectiveness of new drugs. However, there's a lack of data regarding the long-term data on the natural course and how it's managed in China. In this study, we offer a comprehensive overview of clinical and molecular findings, as well as treatment outcomes in the Chinese population. Methods: Institutional data on all patients with dystrophinopathy from August 2011 to August 2021 were retrospectively reviewed. The data included geographic distribution, age at diagnosis, molecular findings, and treatment options, such as corticosteroids, cardiac interventions, and clinical outcomes. Results: In total, 2097 patients with dystrophinopathy, including 1703 cases of Duchenne muscular dystrophy (DMD), 311 cases of Becker muscular dystrophy (BMD), 46 cases of intermediate muscular dystrophy (IMD), and 37 cases categorized as "pending" (individuals with an undetermined phenotype), were registered in the Children's Hospital of Fudan University database for dystrophinopathy from August 2011 to August 2021. The spectrum of identified variants included exonic deletions (66.6%), exonic duplications (10.7%), nonsense variants (10.3%), splice-site variants (4.5%), small deletions (3.5%), small insertions/duplications (1.8%), and missense variants (0.9%). Four deep intronic variants and two inversion variants were identified. Regarding treatment, glucocorticoids were administered to 54.4% of DMD patients and 39.1% of IMD patients. The median age at loss of ambulation was 2.5 years later in DMD patients who received glucocorticoid treatment. Overall, one cardiac medicine at least was prescribed to 7.4% of DMD patients, 8.3% of IMD patients, and 2.6% of BMD patients. Additionally, ventilator support was required by four DMD patients. Eligibility for exon skipping therapy was found in 55.3% of DMD patients, with 12.9%, 10%, and 9.6% of these patients being eligible for skipping exons 51, 53, and 45, respectively. Conclusions: This is one of the largest studies to have evaluated the natural history of dystrophinopathy in China, which is particularly conducive to the recruitment of eligible patients for clinical trials and the provision of real-world data to support drug development. [ABSTRACT FROM AUTHOR]

Background: Malan syndrome (MALNS), previously referred to as "Sotos syndrome 2" due to its resemblance to Sotos syndrome (SS), is an ultra-rare neurodevelopmental disorder characterized by overgrowth, typical craniofacial features, intellectual disability (ID), and a range of psychobehavioral, musculoskeletal, vision and neurological signs. As MALNS and SS partly overlap, it is essential to more accurately profile their clinical presentations and highlight their differences in order to improve syndrome specific management. An increasing number of individuals with MALNS reach adult-age though the natural history of the disorder is poorly characterized due to the small number of adult individuals described so far. As a consequence, current guidelines are limited to the pediatric population. Further delineation of MALNS is essential to optimize care in adulthood. Results: A mixed approach based on cross-sectional data collection with a survey disseminated to caregivers of adults with molecularly confirmed MALNS and literature review was conducted. Twenty-eight caregivers completed the survey. Clinical presentation in adulthood is multisystemic and defined by psychobehavioral comorbidities (96%), musculoskeletal involvement (96%), vision impairment (96%) and neurological complications (86%). The most common signs were anxiety (79%), hypotonia (75%), movement difficulty (75%), scoliosis (64%), problems with coordination (61%), strabismus (57%), constipation (54%), breastbone abnormalities (54%) and advanced bone age during childhood (54%). Impaired vision was complicated by vision decline (36%) and optic atrophy (32%). We report some previously unidentified features, including high pain threshold (46%), incontinence (25%), tremors (21%), muscle hypoplasia (18%) and tics (18%). Conclusions: This survey in the adult population has allowed a more complete description of the natural history of MALNS. Our findings will contribute to the development and improvement of standards of care for adults with MALNS to assure optimal health monitoring and treatment of evolutive complications. We propose additional recommendations to the previous dataset of clinical evaluations specifically applied to adults. The comparison of MALNS and SS adult presentation highlights significant differences in terms of prevalence and severity of ID, behavioral issues, and vision problems, confirming that a proper differential diagnosis between the two conditions is indispensable to guide physicians and mental health professionals to syndrome specific management. [ABSTRACT FROM AUTHOR]

Background: Niemann-Pick disease, type C1 (NPC1) is a rare lysosomal disorder with progressive neurological manifestations, historically recognized as a pediatric disease. However, awareness of the adult-onset (AO) subtype is increasing, often with non-specific symptoms leading to delayed and misdiagnosis. Dysphagia, commonly recognized as a clinical morbidity in NPC1, raises concerns for swallowing safety and aspiration risk. This study aims to characterize swallowing function in AO NPC1, addressing the gap in understanding and clinical management. Methods: Fourteen AO NPC1 individuals in a prospective natural history study (NCT00344331) underwent comprehensive assessments, including history and physical examinations utilizing the NPC1 severity rating scale, videofluoroscopic swallowing studies with summary interpretive analysis, and cerebrospinal fluid (CSF) collection for biomarker evaluation at baseline visit. Descriptive statistics and multivariate statistical modeling were employed to analyze NPC1 disease covariates, along with the American Speech-Language-Hearing Association National Outcome Measure (ASHA-NOMS) and the NIH Penetration Aspiration Scale (NIH-PAS). Results: Our cohort, comprised of 14 predominately female (n = 11, 78.6%) individuals, had an average age of 43.1 ± 16.7 years at the initial visit. Overall, our AO patients were able to swallow independently with no/minimal cueing, with 6 (43%) avoiding specific food items or requiring more time. Upon risk analysis of aspiration, the cohort demonstrated no obvious aspiration risk or laryngeal aspiration in 8 (57%), minimal risk with intermittent laryngeal penetration and retrograde excursion in 5(36%), and moderate risk (7%) in only one. Dietary modifications were recommended in 7 (50%), particularly for liquid viscosities (n = 6, 43%) rather than solids (n = 3, 21%). No significant correlations were identified between swallowing outcomes and NPC1-related parameters or CSF biomarkers. Conclusion: Despite the heterogeneity in NPC1 presentation, the AO cohort displayed functional swallowing abilities with low aspiration risk with some participants still requiring some level of dietary modifications. This study emphasizes the importance of regular swallowing evaluations and management in AO NPC1 to address potential morbidities associated with dysphagia such as aspiration. These findings provide clinical recommendations for the assessment and management of the AO cohort, contributing to improved care for these individuals. [ABSTRACT FROM AUTHOR]

Regulatory marketing authorisation is not enough to ensure patient access to new medicinal products. Health Technology Assessment bodies may require data on effectiveness, relative effectiveness, and cost-effectiveness. Healthcare systems may require data on clinical utility, savings, and budget impact. Furthermore, the exact requirements of these bodies vary country by country and sometimes even region to region, resulting in a patchwork of different data requirements to achieve effective, reimbursed patient access to new therapies. In addition, clinicians require data to make informed clinical management decisions. This requirement is of key importance in rare diseases where there is often limited data and clinical experience at the time of regulatory approval. This paper describes an innovative initiative that is called Project SATURN: Systematic Accumulation of Treatment practices and Utilization, Real world evidence, and Natural history data for the rare disease Osteogenesis Imperfecta. The objective of this project is to generate a common core dataset by utilising existing data sources to meet the needs of the various stakeholders and avoiding fragmentation through multiple approaches (e.g., a series of individual national requests/approaches, and unconnected with the regulators' potential requirements). It is expected that such an approach will reduce the time for patient access to life-changing medications. Whilst Project SATURN applies to Osteogenesis Imperfecta, it is anticipated that the principles could also be applied to other rare diseases and reduce the time for patient access to new medications. [ABSTRACT FROM AUTHOR]

Abstract Background Metachromatic Leukodystrophy (MLD) is a rare, autosomal recessive lysosomal storage disease characterised by the progressive loss of motor function and severe decline in cognitive function. Limited information is available on the burden MLD places on patients and their families and the medical and social support these patients need. Three UK-based MLD patient organisations commissioned an online survey, and follow-up semi-structured interviews to describe and quantify these burdens across MLD subtypes, stage of disease (including end of life) and treatment status (untreated, gene therapy or hematopoietic stem cell transplant [HSCT]). Results A total of 24 patients were included in the study: thirteen late infantile (LI), six early juvenile (EJ), two late juvenile (LJ) and three adult onset (AO). Six patients had received gene therapy and one had received an HSCT. MLD patients receiving no disease modifying treatment bore a high symptom burden: 94% were wheelchair dependent, 88% required tube feeding, 88% were incontinent, 82% had lost their speech and all the children were either unable to attend education or needed specialist provision. Patients were reliant on numerous medical interventions and assistive equipment. All early-onset patients (LI and EJ) were wheelchair dependent, and tube fed, with all EJ patients having lost all speech. The caregiving responsibilities of parents impacted their employment, finances, relationships and health. Patients treated with gene therapy or HSCT were more mobile and were able to eat normally and two thirds of the children were able to attend mainstream school. Conclusions The impact of illness that patients and their caregivers faced was extensive, and the level of care, amount of medication, number of hospital visits and educational support required were substantial. Financial constraints often brought about by inability to work also placed considerable strain on families. The study increases understanding of the burden of MLD on patients and their families, and the level of unmet need in the treatment of the disease.

Abstract Background Protein phosphatase 2 regulatory subunit B’ Delta (PPP2R5D)-related neurodevelopmental disorder is a rare genetic condition caused by pathogenic variants in the PPP2R5D gene. Clinical signs include hypotonia, gross motor delay, intellectual disability (ID), epilepsy, speech delays, and abnormal gait among other impairments. As this disorder was recognized within the last decade, there are only 103 people published diagnoses to date. A thorough understanding of the motor manifestations of this disorder has not yet been established. Knowledge of the natural history of PPP2R5D related neurodevelopmental disorder will lead to improved standard of care treatments as well as serve as a baseline foundation for future clinical trials. Appropriate outcome measures are necessary for use in clinical trials to uniformly measure function and monitor potential for change. The aim of this study was to validate the gross motor function measure (GMFM) in children and adults with PPP2R5D-related neurodevelopmental disorder in order to better characterize the disorder. Results Thirty-eight individuals with PPP2R5D pathogenic variants, median age 8.0 years (range 1–27) were evaluated. Gross motor, upper limb and ambulatory function were assessed using the GMFM-66, six-minute walk test (6MWT), 10-meter walk run (10MWR), timed up and go (TUG), and revised upper limb module (RULM). The pediatric disability inventory computer adapted test (PEDI-CAT) captured caregiver reported assessment. Median GMFM-66 score was 60.6 (SD = 17.3, range 21.1–96.0). There were strong associations between the GMFM-66 and related mobility measures, 10MWR (rs = −0.733; p < 0.001), TUG (rs= −0.747; p = 0.003), 6MWT (r = 0.633; p = 0.006), RULM (r = 0.763; p < 0.001), PEDICAT-mobility (r = 0.855; p < 0.001), and daily activities (r = 0.822; p < 0.001) domains. Conclusions The GMFM is a valid measure for characterizing motor function in individuals with PPP2R5D related neurodevelopmental disorder. The GMFM-66 had strong associations with the RULM and timed function tests which characterized gross motor, upper limb and ambulatory function demonstrating concurrent validity. The GMFM-66 was also able to differentiate between functional levels in PPP2R5D related neurodevelopmental disorder demonstrating discriminant validity. Future studies should examine its sensitivity to change over time, ability to identify sub-phenotypes, and suitability as an outcome measure in future clinical trials in individuals with PPP2R5D variants.

Background: The conduct of rare disease clinical trials is still hampered by methodological problems. The number of patients suffering from a rare condition is variable, but may be very small and unfortunately statistical problems for small and finite populations have received less consideration. This paper describes the outline of the iSTORE project, its ambitions, and its methodological approaches. Methods: In very small populations, methodological challenges exacerbate. iSTORE's ambition is to develop a comprehensive perspective on natural history course modelling through multiple endpoint methodologies, subgroup similarity identification, and improving level of evidence. Results: The methodological approaches cover methods for sound scientific modeling of natural history course data, showing similarity between subgroups, defining, and analyzing multiple endpoints and quantifying the level of evidence in multiple endpoint trials that are often hampered by bias. Conclusion: Through its expected results, iSTORE will contribute to the rare diseases research field by providing an approach to better inform about and thus being able to plan a clinical trial. The methodological derivations can be synchronized and transferability will be outlined. [ABSTRACT FROM AUTHOR]

Background: Implementation of long-chain fatty acid oxidation defects (LCFAOD) in newborn screening (NBS) programs allows for pre-symptomatic diagnosis and treatment. The long-term natural history of NBS LCFAOD patients is largely unknown and may differ from clinically diagnosed pre-NBS patients. This complicates long-term monitoring of LCFAOD and may cause high monitoring variability. To gain insight in current clinical practice, we performed a web-based questionnaire among all metabolic members of the European Reference Network for Hereditary Metabolic Disorders (MetabERN). Results: Thirty-seven colleagues representing at least 35 European metabolic centres shared their experience and results were discussed at the European Metabolic Group (EMG) meeting 2022. The centres concurred in many aspects of long-term monitoring of LCFAOD including the frequency of clinical visits, determination of laboratory parameters, cardiac monitoring and retinopathy screening. Main discrepancies comprised hepatic imaging, glucose monitoring and electrophysiological investigations. Conclusions: Discrepancies may reflect differences in local availability of monitoring tools, the inclusion of LCFAOD in NBS programs as well as differences in local genotypes and phenotypes. Because monitoring strategies are largely based on the natural disease course of clinically identified patients, there might be over-monitoring of some NBS patients. Nevertheless, we advocate long-term monitoring because resulting information is essential to further characterize the natural disease course, develop evidence-based guidelines and provide a basis for evaluation of future therapies. [ABSTRACT FROM AUTHOR]

Abstract Background X-linked hypophosphatemia (XLH) is a rare, hereditary, progressive, renal phosphate-wasting disorder characterized by a pathological increase in FGF23 concentration and activity. Due to its rarity, diagnosis may be delayed, which can adversely affect outcomes. As a chronic disease resulting in progressive accumulation of musculoskeletal manifestations, it is important to understand the natural history of XLH over the patient’s lifetime and the impact of drug treatments and other interventions. This multicentre, international patient registry (International XLH Registry) was established to address the paucity of these data. Here we present the findings of the first interim analysis of the registry. Results The International XLH Registry was initiated in August 2017 and includes participants of all ages diagnosed with XLH, regardless of their treatment and management. At the database lock for this first interim analysis (29 March 2021), 579 participants had entered the registry before 30 November 2020 and are included in the analysis (360 children [62.2%], 217 adults [37.5%] and 2 whose ages were not recorded [0.3%]; 64.2% were female). Family history data were available for 319/345 (92.5%) children and 145/187 (77.5%) adults; 62.1% had biological parents affected by XLH. Genetic testing data were available for 341 (94.7%) children and 203 (93.5%) adults; 370/546 (67.8%) had genetic test results; 331/370 (89.5%) had a confirmed PHEX mutation. A notably longer time to diagnosis was observed in adults ≥ 50 years of age (mean [median] duration 9.4 [2.0] years) versus all adults (3.7 [0.1] years) and children (1.0 [0.2] years). Participants presented with normal weight, shorter length or height and elevated body mass index (approximately − 2 and + 2 Z-scores, respectively) versus the general population. Clinical histories were collected for 349 participants (239 children and 110 adults). General data trends for prevalence of bone, dental, renal and joint conditions in all participants were aligned with expectations for a typical population of people with XLH. Conclusion The data collected within the International XLH Registry, the largest XLH registry to date, provide substantial information to address the paucity of natural history data, starting with demographic, family history, genetic testing, diagnosis, auxology and baseline data on clinical presentation.

Abstract Background Itch is common and distressing in epidermolysis bullosa (EB) but has not previously been studied in depth in different recessive dystrophic EB (RDEB) subtypes. Objectives As part of a prospective register study of the natural history of RDEB we explored features of itch, medications used, and correlation with disease severity and quality of life. Methods Fifty individuals with RDEB aged 8 years and above completed the Leuven Itch Scale (LIS) (total 243 reviews over a 7-year period). Data included itch frequency, severity, duration, distress, circumstances, consequences, itch surface area and medications for itch. The iscorEB disease severity score and the validated EB quality of life tool, QOLEB, were compared to LIS domains and analysed by RDEB subtype. Results Itch was frequent, present in the preceding month in 93% of reviews. Itch severity and distress were significantly greater in severe (RDEB-S) and pruriginosa (RDEB-Pru) subtypes compared to intermediate RDEB (RDEB-I). Itch medications were reported in just over half of reviews including emollients, topical corticosteroids and antihistamines; the proportion of participants not using medication despite frequent pruritus suggests limited efficacy. In inversa RDEB (RDEB-Inv) and RDEB-I, LIS domains correlated with iscorEB and QOLEB. In contrast to previous studies, correlations were lacking in RDEB-S suggesting that global disease burden relatively reduces the contribution of itch. Conclusions This comprehensive study of RDEB-associated itch highlights differences between RDEB subtypes, suggests an unmet need for effective treatments and could serve as control data for future clinical trials incorporating itch as an endpoint.

Background: X-linked hypophosphatemia (XLH) is a rare, hereditary, progressive, renal phosphate-wasting disorder characterized by a pathological increase in FGF23 concentration and activity. Due to its rarity, diagnosis may be delayed, which can adversely affect outcomes. As a chronic disease resulting in progressive accumulation of musculoskeletal manifestations, it is important to understand the natural history of XLH over the patient’s lifetime and the impact of drug treatments and other interventions. This multicentre, international patient registry (International XLH Registry) was established to address the paucity of these data. Here we present the findings of the first interim analysis of the registry. Results: The International XLH Registry was initiated in August 2017 and includes participants of all ages diagnosed with XLH, regardless of their treatment and management. At the database lock for this first interim analysis (29 March 2021), 579 participants had entered the registry before 30 November 2020 and are included in the analysis (360 children [62.2%], 217 adults [37.5%] and 2 whose ages were not recorded [0.3%]; 64.2% were female). Family history data were available for 319/345 (92.5%) children and 145/187 (77.5%) adults; 62.1% had biological parents affected by XLH. Genetic testing data were available for 341 (94.7%) children and 203 (93.5%) adults; 370/546 (67.8%) had genetic test results; 331/370 (89.5%) had a confirmed PHEX mutation. A notably longer time to diagnosis was observed in adults ≥ 50 years of age (mean [median] duration 9.4 [2.0] years) versus all adults (3.7 [0.1] years) and children (1.0 [0.2] years). Participants presented with normal weight, shorter length or height and elevated body mass index (approximately − 2 and + 2 Z-scores, respectively) versus the general population. Clinical histories were collected for 349 participants (239 children and 110 adults). General data trends for prevalence of bone, dental, renal and joint conditions in all participants were aligned with expectations for a typical population of people with XLH. Conclusion: The data collected within the International XLH Registry, the largest XLH registry to date, provide substantial information to address the paucity of natural history data, starting with demographic, family history, genetic testing, diagnosis, auxology and baseline data on clinical presentation. [ABSTRACT FROM AUTHOR]

Background: Generalized pairwise comparisons (GPC) can be used to assess the net benefit of new treatments for rare diseases. We show the potential of GPC through simulations based on data from a natural history study in mucopolysaccharidosis type IIIA (MPS IIIA). Methods: Using data from a historical series of untreated children with MPS IIIA aged 2 to 9 years at the time of enrolment and followed for 2 years, we performed simulations to assess the operating characteristics of GPC to detect potential (simulated) treatment effects on a multi-domain symptom assessment. Two approaches were used for GPC: one in which the various domains were prioritized, the other with all domains weighted equally. The net benefit was used as a measure of treatment effect. We used increasing thresholds of clinical relevance to reflect the magnitude of the desired treatment effects, relative to the standard deviation of the measurements in each domain. Results: GPC were shown to have adequate statistical power (80% or more), even with small sample sizes, to detect treatment effects considered to be clinically worthwhile on a symptom assessment covering five domains (expressive language, daily living skills, and gross-motor, sleep and pain). The prioritized approach generally led to higher power as compared with the non-prioritized approach. Conclusions: GPC of prioritized outcomes is a statistically powerful as well as a patient-centric approach for the analysis of multi-domain scores in MPS IIIA and could be applied to other heterogeneous rare diseases. [ABSTRACT FROM AUTHOR]

Background: Duchenne muscular dystrophy (DMD) is a fatal genetic muscle-wasting disease that affects 1 in 5000 male births with no current cure. Despite great progress has been made in the research of DMD, its underlying pathological mechanism based on the metabolomics is still worthy of further study. Therefore, it is necessary to gain a deeper understanding of the mechanisms or pathogenesis underlying DMD, which may reveal potential therapeutic targets and/or biomarkers. Results: Plasma samples from 42 patients with DMD from a natural history study and 40 age-matched healthy volunteers were subjected to a liquid chromatography-mass spectrometry-based non-targeted metabolomics approach. Acquired metabolic data were evaluated by principal component analysis, partial least squares-discriminant analysis, and metabolic pathway analysis to explore distinctive metabolic patterns in patients with DMD. Differentially expressed metabolites were identified using publicly available and integrated databases. By comparing the DMD and healthy control groups, 25 differential metabolites were detected, including amino acids, unsaturated fatty acids, carnitine, lipids, and metabolites related to the gut microbiota. Correspondingly, linoleic acid metabolism, D-glutamine and D-glutamate metabolism, glycerophospholipid metabolism, and alanine, aspartate, and glutamate metabolism were significantly altered in patients with DMD, compared with those of healthy volunteers. Conclusions: Our study demonstrated the abnormal metabolism of amino acids, energy, and lipids in patients with DMD, consistent with pathological features, such as recurrent muscle necrosis and regeneration, interstitial fibrosis, and fat replacement. Additionally, we found that metabolites of intestinal flora were disordered in DMD patients, providing support for treatment of intestinal microbia disturbance in DMD diseases. Our study provides a new research strategy for understanding the pathogenesis of DMD. [ABSTRACT FROM AUTHOR]

Background: Recently approved treatments for spinal muscular atrophy (SMA) may shift clinical care priorities to secondary complications associated with SMA-related aging. To date, there is little knowledge about the natural history of morbidities across the adult lifespan for SMA. The objective of this study was to identify the prevalence and odds ratio (OR) of various morbidities among adults with vs. without SMA prior to SMA-related treatment. Methods: This was a retrospective cohort study that accessed Medicare fee-for-service and commercial claims data from 01/01/2008-12/22/2016. Data from adults ≥ 18 years old with SMA and without SMA matched (1:200 case:control) on demographics, region, and study entry year were included. The prevalence of 30 morbidities across physiologic systems (e.g., cardiovascular, metabolic, musculoskeletal, urinary) and mental health disorders was examined. Age- and sex-adjusted OR was estimated using logistic regression for each morbidity and effect modification by age and sex was tested. Results: There were 2,427 adults with SMA (mean [SD] age, 59.7 [17.4] years; 49.0% female) and 484,528 matched adults without SMA. Adults with vs. without SMA had a higher prevalence and adjusted OR of all 30 morbidities, ranging from OR = 1.61 (95% CI = 1.45–1.80) for hypothyroidism to OR = 7.80 (95% CI = 7.10–8.57) for fluid/electrolyte disorders. There was effect modification by age for 24 morbidities. The OR was highest for the youngest age group (18–40 years; OR range, 2.38 to 117.7; all P < 0.05) and declined with older age groups, but still remained significantly elevated in the oldest age group (≥ 75 years; OR range, 1.30 to 5.96; all P < 0.05). Conclusions: The limitations of this study are that evidence of morbidities were limited to diagnostic claims and information on SMA type and symptoms or onset were not available. In conclusion, adults with SMA had a higher and earlier prevalence of a variety of morbidities across physiological systems and mental health disorders. [ABSTRACT FROM AUTHOR]

Background: X-linked adrenoleukodystrophy (ALD) is a rare metabolic and neurodegenerative disorder belonging to the group of leukodystrophies, with an estimated incidence around 1:25 000 newborns worldwide, mostly among men. Childhood Cerebral ALD (CCALD) is the most severe form with a poor prognosis if not properly treated during the first years of life. Currently, only allogeneic hematopoietic stem cell transplantation (allo-HSCT) is widely available for CCALD treatment. To date, there is a lack of data regarding CCALD epidemiology, natural history, and current management in France. This knowledge is crucial for the development of new therapies such as gene therapies. In this context, the French National Health Data System (SNDS) is a particularly indicated database to collect information meeting these needs. A non-interventional, national, real-life, retrospective study was performed using secondary data from the national ALD registry (LEUKOFRANCE) and SNDS. CCALD patients detected between 2009 and 2018 and successfully matched between LEUKOFRANCE and SNDS were included in this study. Index date was defined as the first CCALD event detected during study period. Subgroups of patients with sufficient follow-up (6 months) and history (1 year) available around index date were analyzed to assess CCALD burden and natural history. Results: 52 patients were included into the matched cohort. Median annual incidence of CCALD was estimated at 4 patients. Median age at CCALD diagnosis was 7.0 years. Among patients without allo-HSCT, five-year overall survival was 66.6%, with 93.3% of them presenting at least one CCALD symptom and 62.1% presenting a least one major functional disability (MFD). Among patients with allo-HSCT, five-year overall survival was 94.4%, with only 11.1% of patients presenting CCALD symptoms, and 16.7% of presenting a MFD. Mean annualized costs were almost twice as important among patients without allo-HSCT, with 49,211€, 23,117€, respectively. Costs were almost exclusively represented by hospitalizations. Conclusions: To the best of our knowledge, this is the most up to date study analyzing CCALD epidemiology, clinical and economic burden in France. The necessity of a precocious management with HSCT highlight the potential benefits of including an expanded screening program among newborns, coupled with family screenings when a mutation is detected. [ABSTRACT FROM AUTHOR]

Background: Itch is common and distressing in epidermolysis bullosa (EB) but has not previously been studied in depth in different recessive dystrophic EB (RDEB) subtypes. Objectives: As part of a prospective register study of the natural history of RDEB we explored features of itch, medications used, and correlation with disease severity and quality of life. Methods: Fifty individuals with RDEB aged 8 years and above completed the Leuven Itch Scale (LIS) (total 243 reviews over a 7-year period). Data included itch frequency, severity, duration, distress, circumstances, consequences, itch surface area and medications for itch. The iscorEB disease severity score and the validated EB quality of life tool, QOLEB, were compared to LIS domains and analysed by RDEB subtype. Results: Itch was frequent, present in the preceding month in 93% of reviews. Itch severity and distress were significantly greater in severe (RDEB-S) and pruriginosa (RDEB-Pru) subtypes compared to intermediate RDEB (RDEB-I). Itch medications were reported in just over half of reviews including emollients, topical corticosteroids and antihistamines; the proportion of participants not using medication despite frequent pruritus suggests limited efficacy. In inversa RDEB (RDEB-Inv) and RDEB-I, LIS domains correlated with iscorEB and QOLEB. In contrast to previous studies, correlations were lacking in RDEB-S suggesting that global disease burden relatively reduces the contribution of itch. Conclusions: This comprehensive study of RDEB-associated itch highlights differences between RDEB subtypes, suggests an unmet need for effective treatments and could serve as control data for future clinical trials incorporating itch as an endpoint. [ABSTRACT FROM AUTHOR]

Abstract Background Achondroplasia, caused by a pathogenic variant in the fibroblast growth factor receptor 3 gene, is the most common skeletal dysplasia. The Lifetime Impact of Achondroplasia Study in Europe (LIAISE; NCT03449368) aimed to quantify the burden of achondroplasia among individuals across a broad range of ages, including adults. Methods Demographic, clinical and healthcare resource use data were collected from medical records of achondroplasia patients enrolled in 13 sites across six European countries in this retrospective, observational study. Descriptive statistics or event rates per 100 person-years were calculated and compared across age groups as well as by history of limb lengthening. Patient-reported outcomes (quality of life [QoL], pain, functional independence, work productivity and activity impairments) were evaluated using questionnaires at the time of enrolment. An exploratory analysis investigated correlations between height (z-score or centimetres) and patient-reported outcomes. Results Overall, 186 study patients were included, with a mean age of 21.7 ± 17.3 years (range 5.0–84.4). At least one complication or surgery was reported for 94.6% and 72.0% of patients, respectively, at a rate of 66.6 and 21.5 events per 100 person-years. Diverse medical and surgical complications were reported for all ages in a bimodal distribution, occurring more frequently in the youngest and oldest age groups. A total of 40 patients had previously undergone limb lengthening (capped at 20% per the study protocol). The most frequent surgery types varied by age, in line with complication profiles. Healthcare resource use was high across all age groups, especially among the youngest and oldest individuals, and did not differ substantially according to history of limb lengthening. Compared to general population values, patients reported impaired QoL particularly for physical functioning domains. In addition, patients reported difficulty carrying out daily activities independently and pain starting in childhood. Patient height correlated with multiple patient-reported outcomes. Conclusions The findings of this study suggest that, across an individual’s lifetime, achondroplasia is associated with multisystem complications, reduced QoL and functionality, and increased pain. These results highlight the large amount of healthcare resources that individuals with achondroplasia require throughout their lifespans and provide novel insights into current achondroplasia management practices across Europe. Trial registration ClinicalTrials.gov, NCT03449368, Submitted 14 December 2017 – prospectively registered, https://clinicaltrials.gov/ct2/show/record/NCT03449368

Abstract Background Porphyrias are a rare group of disease due to inherited defects of heme synthesis with important systemic manifestations and great burden of disease for patients and families due to the exceptional course of disease with disabling chronic symptoms interposed by life-threatening acute attacks. Unfortunately, the porphyrias are usually underrecognized reflecting a lack of medical and disease awareness as well as few studies about natural history in large cohorts of patients. The main aim of this article is present consistent data about natural history and burden of disease in a large Brazilian cohort. Methods We conducted a national cross-sectional registry with retrospective clinical data of Brazilian patients with porphyria collected with Brazilian patients Association with Porphyria in collaboration with a tertiary care center for rare diseases. Results A cohort of 172 patients was analyzed in which 148 (86%) patients had the diagnosis of acute hepatic porphyria [AHP] that needed a mean of 62.04 medical visits and 9.6 years to achieve a definitive diagnosis. About AHP cohort, the most common first clinical manifestation were abdominal pain in 77 (52%) patients and acute muscle weakness in 23 (15.5%) with 73 (49.3%) patients presenting only one attack during disease course and 37 (25%) exhibiting 4 or more attacks in the last year. Of note, 105 patients with AHP reported chronic manifestations and the scores for quality of life are lower when compared with general healthy population. Conclusions Brazilian patients with AHP had a higher prevalence of chronic disabling manifestations and a poor quality of life like other cohorts and a higher proportion of patients with recurrent attacks than previously reported.

Abstract Background Progressive lung function decline, resulting in respiratory failure, is an important complication of spinal muscular atrophy (SMA). The ability to predict the need for mechanical ventilation is important. We assessed longitudinal patterns of lung function prior to chronic respiratory failure in a national cohort of treatment-naïve children and adults with SMA, hypothesizing an accelerated decline prior to chronic respiratory failure. Methods We included treatment-naïve SMA patients participating in a prospective national cohort study if they required mechanical ventilation because of chronic respiratory failure and if lung function test results were available from the years prior to initiation of ventilation. We analyzed Forced Vital Capacity (FVC), Forced Expiratory Volume in 1 s (FEV1), Peak Expiratory Flow (PEF) and Maximum Expiratory Pressure (PEmax). We studied the longitudinal course using linear mixed-effects models. We compared patients who electively started mechanical ventilation compared to patients who could not be weaned after acute respiratory failure. Results We analyzed 385 lung function tests from 38 patients with SMA types 1c–3a. At initiation of ventilation median age was 18.8 years (IQR: 13.2–30.1) and median standardized FVC, FEV1 and PEF were 28.8% (95% CI: 23.5; 34.2), 28.8% (95% CI: 24.0; 33.7) and 30.0% (95% CI: 23.4; 36.7), with an average annual decline of 1.75% (95% CI: 0.86; 2.66), 1.72% (95% CI: 1.04; 2.40) and 1.65% (95% CI: 0.71; 2.59), respectively. Our data did not support the hypothesis of an accelerated decline prior to initiation of mechanical ventilation. Median PEmax was 35.3 cmH2O (95% CI: 29.4; 41.2) at initiation of mechanical ventilation and relatively stable in the years preceding ventilation. Median FVC, FEV1, PEF and PEmax were lower in patients who electively started mechanical ventilation (p

Abstract Pearson syndrome (PS) is a rare fatal mitochondrial disorder caused by single large-scale mitochondrial DNA deletions (SLSMDs). Most patients present with anemia in infancy. Bone marrow cytology with vacuolization in erythroid and myeloid precursors and ring-sideroblasts guides to the correct diagnosis, which is established by detection of SLSMDs. Non hematological symptoms suggesting a mitochondrial disease are often lacking at initial presentation, thus PS is an important differential diagnosis in isolated hypogenerative anemia in infancy. Spontaneous resolution of anemia occurs in two-third of patients at the age of 1–3 years, while multisystem non-hematological complications such as failure to thrive, muscle hypotonia, exocrine pancreas insufficiency, renal tubulopathy and cardiac dysfunction develop during the clinical course. Some patients with PS experience a phenotypical change to Kearns-Sayre syndrome. In the absence of curative therapy, the prognosis of patients with PS is dismal. Most patients die of acute lactic acidosis and multi-organ failure in early childhood. There is a great need for the development of novel therapies to alter the natural history of patients with PS.

Background: Collection of real-world evidence (RWE) is important in achondroplasia. Development of a prospective, shared, international resource that follows the principles of findability, accessibility, interoperability, and reuse of digital assets, and that captures long-term, high-quality data, would improve understanding of the natural history of achondroplasia, quality of life, and related outcomes. Methods: The Europe, Middle East, and Africa (EMEA) Achondroplasia Steering Committee comprises a multidisciplinary team of 17 clinical experts and 3 advocacy organization representatives. The committee undertook an exercise to identify essential data elements for a standardized prospective registry to study the natural history of achondroplasia and related outcomes. Results: A range of RWE on achondroplasia is being collected at EMEA centres. Whereas commonalities exist, the data elements, methods used to collect and store them, and frequency of collection vary. The topics considered most important for collection were auxological measures, sleep studies, quality of life, and neurological manifestations. Data considered essential for a prospective registry were grouped into six categories: demographics; diagnosis and patient measurements; medical issues; investigations and surgical events; medications; and outcomes possibly associated with achondroplasia treatments. Conclusions: Long-term, high-quality data are needed for this rare, multifaceted condition. Establishing registries that collect predefined data elements across age spans will provide contemporaneous prospective and longitudinal information and will be useful to improve clinical decision-making and management. It should be feasible to collect a minimum dataset with the flexibility to include country-specific criteria and pool data across countries to examine clinical outcomes associated with achondroplasia and different therapeutic approaches. [ABSTRACT FROM AUTHOR]

Background: The purpose of this study was to describe the frequency and risk factors for orthopedic surgery in patients with achondroplasia. CLARITY (The Achondroplasia Natural History Study) includes clinical data from achondroplasia patients receiving treatment at four skeletal dysplasia centers in the United States from 1957 to 2018. Data were entered and stored in a Research Electronic Data Capture (REDCap) database. Results: Information from one thousand three hundred and seventy-four patients with achondroplasia were included in this study. Four hundred and eight (29.7%) patients had at least one orthopedic surgery during their lifetime and 299 (21.8%) patients underwent multiple procedures. 12.7% (n = 175) of patients underwent spine surgery at a mean age at first surgery of 22.4 ± 15.3 years old. The median age was 16.7 years old (0.1–67.4). 21.2% (n = 291) of patients underwent lower extremity surgery at a mean age at first surgery of 9.9 ± 8.3 years old with a median age of 8.2 years (0.2–57.8). The most common spinal procedure was decompression (152 patients underwent 271 laminectomy procedures), while the most common lower extremity procedure was osteotomy (200 patients underwent 434 procedures). Fifty-eight (4.2%) patients had both a spine and lower extremity surgery. Specific risk factors increasing the likelihood of orthopedic surgery included: patients with hydrocephalus requiring shunt placement having higher odds of undergoing spine surgery (OR 1.97, 95% CI 1.14–3.26); patients having a cervicomedullary decompression also had higher odds of undergoing spine surgery (OR 1.85, 95% CI 1.30–2.63); and having lower extremity surgery increased the odds of spine surgery (OR 2.05, 95% CI 1.45–2.90). Conclusions: Orthopedic surgery was a common occurrence in achondroplasia with 29.7% of patients undergoing at least one orthopedic procedure. Spine surgery (12.7%) was less common and occurred at a later age than lower extremity surgery (21.2%). Cervicomedullary decompression and hydrocephalus with shunt placement were associated with an increased risk for spine surgery. The results from CLARITY, the largest natural history study of achondroplasia, should aid clinicians in counseling patients and families about orthopedic surgery. [ABSTRACT FROM AUTHOR]

Abstract Background Alpha-mannosidosis is a rare autosomal recessive lysosomal storage disorder (LSD) caused by reduced activity of alpha-mannosidase. Clinical manifestations include skeletal dysmorphism, mental impairment, hearing loss and recurrent infections. The severe type of the disease leads to early childhood death, while patients with milder forms can live into adulthood. There are no mortality studies to date. This study aimed to investigate the age at death and the causes of death of patients with alpha-mannosidosis who had not received disease-modifying treatment. Methods Clinicians and LSD patient organisations (POs) from 33 countries were invited to complete a questionnaire between April–May 2021. Cause of death and age at death was available for 15 patients. A literature review identified seven deceased patients that met the inclusion criteria. Results Median age at death for patients reported by clinicians/POs was 45 years (mean 40.3 ± 13.2, range 18–56, n = 15); 53% were female. One death occurred during the patient’s second decade of life, and 14 out of 15 deaths (93.3%) during or after the patients’ third decade, including four (26.7%) during their sixth decade. Median age at death for patients identified from the literature was 4.3 years (mean 15.7 ± 17.0, range 2.2–41, n = 7); two were female. Four of the seven patients (57.1%) died within the first decade of life. Seven of 15 deaths (46.7%) reported by clinicians/POs were recorded as pneumonia and three (20.0%) as cancer. Other causes of death included acute renal failure due to sepsis after intestinal perforation, decrease of red blood cells of unknown origin, kidney failure with systemic lupus erythematosus, aortic valve insufficiency leading to heart failure, and dehydration due to catatonia. Three out of seven causes of death (42.9%) reported in the literature were associated with septicaemia, two (28.6%) with respiratory failure and one to pneumonia following aspiration. Conclusions This study suggests that pneumonia has been the primary cause of death during recent decades in untreated patients with alpha-mannosidosis, followed by cancer. Determining the causes of mortality and life expectancy in these patients is crucial to further improve our understanding of the natural history of alpha-mannosidosis.

Background: Achondroplasia, caused by a pathogenic variant in the fibroblast growth factor receptor 3 gene, is the most common skeletal dysplasia. The Lifetime Impact of Achondroplasia Study in Europe (LIAISE; NCT03449368) aimed to quantify the burden of achondroplasia among individuals across a broad range of ages, including adults. Methods: Demographic, clinical and healthcare resource use data were collected from medical records of achondroplasia patients enrolled in 13 sites across six European countries in this retrospective, observational study. Descriptive statistics or event rates per 100 person-years were calculated and compared across age groups as well as by history of limb lengthening. Patient-reported outcomes (quality of life [QoL], pain, functional independence, work productivity and activity impairments) were evaluated using questionnaires at the time of enrolment. An exploratory analysis investigated correlations between height (z-score or centimetres) and patient-reported outcomes. Results: Overall, 186 study patients were included, with a mean age of 21.7 ± 17.3 years (range 5.0–84.4). At least one complication or surgery was reported for 94.6% and 72.0% of patients, respectively, at a rate of 66.6 and 21.5 events per 100 person-years. Diverse medical and surgical complications were reported for all ages in a bimodal distribution, occurring more frequently in the youngest and oldest age groups. A total of 40 patients had previously undergone limb lengthening (capped at 20% per the study protocol). The most frequent surgery types varied by age, in line with complication profiles. Healthcare resource use was high across all age groups, especially among the youngest and oldest individuals, and did not differ substantially according to history of limb lengthening. Compared to general population values, patients reported impaired QoL particularly for physical functioning domains. In addition, patients reported difficulty carrying out daily activities independently and pain starting in childhood. Patient height correlated with multiple patient-reported outcomes. Conclusions: The findings of this study suggest that, across an individual's lifetime, achondroplasia is associated with multisystem complications, reduced QoL and functionality, and increased pain. These results highlight the large amount of healthcare resources that individuals with achondroplasia require throughout their lifespans and provide novel insights into current achondroplasia management practices across Europe. Trial registration ClinicalTrials.gov, NCT03449368, Submitted 14 December 2017 – prospectively registered, https://clinicaltrials.gov/ct2/show/record/NCT03449368 [ABSTRACT FROM AUTHOR]

Background: Porphyrias are a rare group of disease due to inherited defects of heme synthesis with important systemic manifestations and great burden of disease for patients and families due to the exceptional course of disease with disabling chronic symptoms interposed by life-threatening acute attacks. Unfortunately, the porphyrias are usually underrecognized reflecting a lack of medical and disease awareness as well as few studies about natural history in large cohorts of patients. The main aim of this article is present consistent data about natural history and burden of disease in a large Brazilian cohort. Methods: We conducted a national cross-sectional registry with retrospective clinical data of Brazilian patients with porphyria collected with Brazilian patients Association with Porphyria in collaboration with a tertiary care center for rare diseases. Results: A cohort of 172 patients was analyzed in which 148 (86%) patients had the diagnosis of acute hepatic porphyria [AHP] that needed a mean of 62.04 medical visits and 9.6 years to achieve a definitive diagnosis. About AHP cohort, the most common first clinical manifestation were abdominal pain in 77 (52%) patients and acute muscle weakness in 23 (15.5%) with 73 (49.3%) patients presenting only one attack during disease course and 37 (25%) exhibiting 4 or more attacks in the last year. Of note, 105 patients with AHP reported chronic manifestations and the scores for quality of life are lower when compared with general healthy population. Conclusions: Brazilian patients with AHP had a higher prevalence of chronic disabling manifestations and a poor quality of life like other cohorts and a higher proportion of patients with recurrent attacks than previously reported. [ABSTRACT FROM AUTHOR]

Background: Progressive lung function decline, resulting in respiratory failure, is an important complication of spinal muscular atrophy (SMA). The ability to predict the need for mechanical ventilation is important. We assessed longitudinal patterns of lung function prior to chronic respiratory failure in a national cohort of treatment-naïve children and adults with SMA, hypothesizing an accelerated decline prior to chronic respiratory failure. Methods: We included treatment-naïve SMA patients participating in a prospective national cohort study if they required mechanical ventilation because of chronic respiratory failure and if lung function test results were available from the years prior to initiation of ventilation. We analyzed Forced Vital Capacity (FVC), Forced Expiratory Volume in 1 s (FEV1), Peak Expiratory Flow (PEF) and Maximum Expiratory Pressure (PEmax). We studied the longitudinal course using linear mixed-effects models. We compared patients who electively started mechanical ventilation compared to patients who could not be weaned after acute respiratory failure. Results: We analyzed 385 lung function tests from 38 patients with SMA types 1c–3a. At initiation of ventilation median age was 18.8 years (IQR: 13.2–30.1) and median standardized FVC, FEV1 and PEF were 28.8% (95% CI: 23.5; 34.2), 28.8% (95% CI: 24.0; 33.7) and 30.0% (95% CI: 23.4; 36.7), with an average annual decline of 1.75% (95% CI: 0.86; 2.66), 1.72% (95% CI: 1.04; 2.40) and 1.65% (95% CI: 0.71; 2.59), respectively. Our data did not support the hypothesis of an accelerated decline prior to initiation of mechanical ventilation. Median PEmax was 35.3 cmH2O (95% CI: 29.4; 41.2) at initiation of mechanical ventilation and relatively stable in the years preceding ventilation. Median FVC, FEV1, PEF and PEmax were lower in patients who electively started mechanical ventilation (p < 0.001). Conclusions: Patterns of lung function decline cannot predict impending respiratory failure: SMA is characterized by a gradual decline of lung function. We found no evidence for an accelerated deterioration. In addition, PEmax remains low and stable in the years preceding initiation of ventilation. Patients who electively started mechanical ventilation had more restrictive lung function at initiation of ventilation, compared to patients who could not be weaned after surgery or a respiratory tract infection. [ABSTRACT FROM AUTHOR]

Abstract Background The natural history and genotype–phenotype correlation of Pelizaeus–Merzbacher disease (PMD) of Chinese patients has been rarely reported. Method Patients who met the criteria for PMD were enrolled in our study. Genomic analysis was conducted by multiplex ligation probe amplification (MLPA) and Sanger or whole-exome sequencing (WES). Natural history differences and genotype–phenotype correlations were analyzed. Result A total of 111 patients were enrolled in our follow-up study. The median follow-up interval was 53 m (1185). Among PMD patients, developmental delay was the most common sign, and nystagmus and hypotonia were the most common initial symptoms observed. A total of 78.4% of the patients were able to control their head, and 72.1% could speak words. However, few of the patients could stand (9.0%) or walk (4.5%) by themselves. Nystagmus improved in more than half of the patients, and hypotonia sometimes deteriorated to movement disorders. More PLP1 point mutations patients were categorized into severe group, while more patients with PLP1 duplications were categorized into mild group (p

Abstract Background Respiratory complications are the most important cause of morbidity and mortality in spinal muscular atrophy (SMA). Respiratory muscle weakness results in impaired cough, recurrent respiratory tract infections and eventually can cause respiratory failure. We assessed longitudinal patterns of respiratory muscle strength in a national cohort of treatment-naïve children and adults with SMA, hypothesizing a continued decline throughout life. Methods We measured maximal expiratory and inspiratory pressure (PEmax and PImax), Sniff Nasal inspiratory pressure (SNIP), peak expiratory flow (PEF), and peak cough flow (PCF) in treatment-naïve patients with SMA. We used mixed-models to analyze natural history patterns. Results We included 2172 measurements of respiratory muscle function from 80 treatment-naïve patients with SMA types 1c-3b. All outcomes were lower in the more severe phenotypes. Significant differences in PEF were present between SMA types from early ages onwards. PEF decline was linear (1–2%/year). PEF reached values below 80% during early childhood in types 1c-2, and during adolescence in type 3a. PEmax and PImax were severely lowered in most patients throughout life, with PEmax values abnormally low (i.e.

Pearson syndrome (PS) is a rare fatal mitochondrial disorder caused by single large-scale mitochondrial DNA deletions (SLSMDs). Most patients present with anemia in infancy. Bone marrow cytology with vacuolization in erythroid and myeloid precursors and ring-sideroblasts guides to the correct diagnosis, which is established by detection of SLSMDs. Non hematological symptoms suggesting a mitochondrial disease are often lacking at initial presentation, thus PS is an important differential diagnosis in isolated hypogenerative anemia in infancy. Spontaneous resolution of anemia occurs in two-third of patients at the age of 1-3 years, while multisystem non-hematological complications such as failure to thrive, muscle hypotonia, exocrine pancreas insufficiency, renal tubulopathy and cardiac dysfunction develop during the clinical course. Some patients with PS experience a phenotypical change to Kearns-Sayre syndrome. In the absence of curative therapy, the prognosis of patients with PS is dismal. Most patients die of acute lactic acidosis and multi-organ failure in early childhood. There is a great need for the development of novel therapies to alter the natural history of patients with PS. [ABSTRACT FROM AUTHOR]

Purpose: Aicardi syndrome is a rare epileptic encephalopathy, almost exclusively affecting girls. It was first described as a triad of infantile spasms, chorioretinal defects and agenesis of the corpus callosum. The etiology remains unknown and there is uncertainty on best practice therapy and outcome. We aimed at defining quantitative clinical endpoints that will inform future research and clinical trials., Methods: Quantitative natural history modeling of cases with Aicardi syndrome from published clinical reports. Main outcome measures were age at disease onset, survival and diagnostic delay. Phenotypic features of affected individuals as well as neuroradiological and ophthalmological features were descriptively stated. STROBE criteria were respected., Results: Two hundred forty-five cases were available for analysis. Median age at disease onset was 2.2 months. Median diagnostic delay was 1 month. Mortality was estimated with 6% at 1 and 17% at 5 years of age. 60% of children showed the classic clinical features, while 40% met the revised diagnostic criteria. We delineate possible predictors of disease severity and of seizure control., Conclusion: We provide natural history data including geographical localization of 245 published patients with Aicardi syndrome. Quantitative history modeling in rare epileptic encephalopathies will help to raise disease awareness and facilitate future clinical trials as one core element of quantitative systems pharmacology., Competing Interests: Declarations. Ethics approval and consent to participate: Not applicable. Consent for publication: Not applicable. Competing interests: O.U. declares that he has no competing interests. G.F.H. declares that he has no competing interests. S.K. declares that he has no competing interests. S.S. declares that he has no competing interests., (© 2024. The Author(s).)

Abstract Background Understanding the natural history of rare bone and mineral conditions is essential for improving clinical practice and the development of new diagnostics and therapeutics. Recruitment and long-term participation in registries are key challenges for researchers. Methods To understand the user needs, the European Reference Network on Rare Bone Diseases (ERN BOND) and European Patient Advocacy Groups developed and implemented a multinational survey about the patient’s preferred database content and functionality through an iterative consensus process. The survey was disseminated by national and international patient groups and healthcare professionals. The findings were analysed using descriptive statistics and multivariate regression. Results There were 493 eligible responses from 378 adults, 15 children and 100 parents, guardians or carers (PGC) across 22 rare bone and mineral conditions. Osteogenesis imperfecta constituted 53.4% of responses. Contents related to improving treatment and medical services scored the highest and contents about anxiety and socializing scored less highly. Additional content was recommended by 205 respondents. Respondents preferred data entry by their Healthcare Provider (HCP). However, less than 50% of adults received followup from their specialist HCP at least annually and 29% were followed up as needed. Conclusions This survey of individuals, their family, guardians and carers has prioritised the key components for an EU-based rare bone and mineral condition research database. The survey highlights issues around collecting psychosocial impacts as well as measures of HCP trust. The survey demonstrated that using only specialist centre visits for data collection, while preferred by patients, will miss a substantial number of individuals, limiting generalisability. Combined HCP and patient platforms will be required to collect representative and complete natural history data for this patient group.

Background: Natural history studies are increasingly recognized as having an important role in drug development for rare diseases. A phase 3, observational, retrospective, and non-interventional study was designed to establish a natural history control (NHC) cohort of patients with Barth syndrome (BTHS) to provide further analysis of the efficacy of elamipretide observed in an open-label extension (OLE) phase of the TAZPOWER trial, a clinical trial that tested the efficacy of 40 mg daily of elamipretide in patients with BTHS.Methods: This was a retrospective, non-interventional study. A propensity score model was used to compare elamipretide-treated patients and NHCs. The analysis included 8 patients from the TAZPOWER OLE and 19 untreated NHCs (including 12 with serial echocardiographic assessments).Results: For the 6-min walk test (6MWT, primary endpoint), the least squares (LS) mean difference between groups was 79.7 m (P = 0.0004) at week 64 and 91.0 m (P = 0.0005) at week 76 in favor of elamipretide. Significant improvements in muscle strength (secondary endpoint), as assessed by handheld dynamometry (HHD) were also observed with elamipretide, with LS mean differences of 40.8 Newtons at 64 weeks (P = 0.0002) and 56.7 Newtons at 76 weeks (P = 0.0005). Patients continuously treated with elamipretide also experienced statistically significant improvements in other secondary endpoints (i.e., 5 times sit-to-stand [5XSST], multi-domain responder index [MDRI]). The functional improvements were robust to sensitivity analyses. Left ventricular stroke volume increased from baseline in patients with elamipretide but decreased in NHCs.Conclusions: Overall, the study established a NHC for use in assessing the efficacy of therapeutic interventions in patients with BTHS and the results suggest that elamipretide may improve natural history of BTHS at least in part by attenuating the natural decline in heart function and provide meaningful improvements in heart function and functional capacity in patients with BTHS compared to NHCs.Highlights: A matched Natural History Control (NHC) was used to evaluate elamipretide in BTHS Elamipretide may improve natural history of BTHS by attenuating natural decline in heart function Elamipretide was associated with meaningful clinical improvements in skeletal muscle and cardiovascular parameters that were not observed in NHCs The study established a NHC for use in assessing the efficacy of therapeutic interventions in BTHS. [ABSTRACT FROM AUTHOR]

Background: Alpha-mannosidosis is a rare autosomal recessive lysosomal storage disorder (LSD) caused by reduced activity of alpha-mannosidase. Clinical manifestations include skeletal dysmorphism, mental impairment, hearing loss and recurrent infections. The severe type of the disease leads to early childhood death, while patients with milder forms can live into adulthood. There are no mortality studies to date. This study aimed to investigate the age at death and the causes of death of patients with alpha-mannosidosis who had not received disease-modifying treatment.Methods: Clinicians and LSD patient organisations (POs) from 33 countries were invited to complete a questionnaire between April-May 2021. Cause of death and age at death was available for 15 patients. A literature review identified seven deceased patients that met the inclusion criteria.Results: Median age at death for patients reported by clinicians/POs was 45 years (mean 40.3 ± 13.2, range 18-56, n = 15); 53% were female. One death occurred during the patient's second decade of life, and 14 out of 15 deaths (93.3%) during or after the patients' third decade, including four (26.7%) during their sixth decade. Median age at death for patients identified from the literature was 4.3 years (mean 15.7 ± 17.0, range 2.2-41, n = 7); two were female. Four of the seven patients (57.1%) died within the first decade of life. Seven of 15 deaths (46.7%) reported by clinicians/POs were recorded as pneumonia and three (20.0%) as cancer. Other causes of death included acute renal failure due to sepsis after intestinal perforation, decrease of red blood cells of unknown origin, kidney failure with systemic lupus erythematosus, aortic valve insufficiency leading to heart failure, and dehydration due to catatonia. Three out of seven causes of death (42.9%) reported in the literature were associated with septicaemia, two (28.6%) with respiratory failure and one to pneumonia following aspiration.Conclusions: This study suggests that pneumonia has been the primary cause of death during recent decades in untreated patients with alpha-mannosidosis, followed by cancer. Determining the causes of mortality and life expectancy in these patients is crucial to further improve our understanding of the natural history of alpha-mannosidosis. [ABSTRACT FROM AUTHOR]

Abstract Background LAMA2-related muscular dystrophy including LAMA2-related congenital muscular dystrophy (LAMA2-CMD) and autosomal recessive limb-girdle muscular dystrophy-23 (LGMDR23) is caused by LAMA2 pathogenic variants. We aimed to describe the natural history and establish genotype–phenotype correlations in a large cohort of Chinese patients with LAMA2-related muscular dystrophy. Methods Clinical and genetic data of LAMA2-related muscular dystrophy patients enrolled from ten research centers between January 2003 and March 2021 were collected and analyzed. Results One hundred and thirty patients (116 LAMA2-CMD and 14 LGMDR23) were included. LAMA2-CMD group had earlier onset than LGMDR23 group. Head control, independent sitting and ambulation were achieved in 76.3%, 92.6% and 18.4% of LAMA2-CMD patients at median ages of 6.0 months (range 2.0–36.0 months), 11.0 months (range 6.0–36.0 months), and 27.0 months (range 18.0–84.0 months), respectively. All LGMDR23 patients achieved independent ambulation at median age of 18.0 months (range 13.0–20.0 months). Motor regression in LAMA2-CMD mainly occurred concurrently with rapid progression of contractures during 6–9 years old. Twenty-four LAMA2-related muscular dystrophy patients died, mostly due to severe pneumonia. Seizures occurred in 35.7% of LGMDR23 and 9.5% of LAMA2-CMD patients. Forty-six novel and 97 known LAMA2 disease-causing variants were identified. The top three high-frequency disease-causing variants in Han Chinese patients were c.7147C > T (p.R2383*), exon 4 deletion, and c.5156_5159del (p.K1719Rfs*5). In LAMA2-CMD, splicing variants tended to be associated with a relatively mild phenotype. Nonsense variants were more frequent in LAMA2-CMD (56.9%, 66/116) than in LGMDR23 (21.4%, 3/14), while missense disease-causing variants were more frequent in LGMDR23 (71.4%, 10/14) than in LAMA2-CMD (12.9%, 15/116). Copy number variations were identified in 26.4% of survivors and 50.0% of nonsurvivors, suggesting that copy number variations were associated with lower rate of survival (p = 0.029). Conclusions This study provides better understandings of natural history and genotype–phenotype correlations in LAMA2-related muscular dystrophy, and supports therapeutic targets for future researches.

Abstract Background Rare diseases are estimated to affect 150–350 million people worldwide. With advances in next generation sequencing, the number of known disease-causing genes has increased significantly, opening the door for therapy development. Rare disease research has therefore pivoted from gene discovery to the exploration of potential therapies. With impending clinical trials on the horizon, researchers are in urgent need of natural history studies to help them identify surrogate markers, validate outcome measures, define historical control patients, and design therapeutic trials. Results We customized a browser-accessible multi-modal (e.g. genetics, imaging, behavioral, patient-determined outcomes) database to increase cohort sizes, identify surrogate markers, and foster international collaborations. Ninety data entry forms were developed including family, perinatal, developmental history, clinical examinations, diagnostic investigations, neurological evaluations (i.e. spasticity, dystonia, ataxia, etc.), disability measures, parental stress, and quality of life. A customizable clinical letter generator was created to assist in continuity of patient care. Conclusions Small cohorts and underpowered studies are a major challenge for rare disease research. This online, rare disease database will be accessible from all over the world, making it easier to share and disseminate data. We have outlined the methodology to become Title 21 Code of Federal Regulations Part 11 Compliant, which is a requirement to use electronic records as historical controls in clinical trials in the United States. Food and Drug Administration compliant databases will be life-changing for patients and families when historical control data is used for emerging clinical trials. Future work will leverage these tools to delineate the natural history of several rare diseases and we are confident that this database will be used on a larger scale to improve care for patients affected with rare diseases.

Abstract Background Acid sphingomyelinase deficiency (ASMD) (also known as Niemann-Pick disease types A and B) is a rare and debilitating lysosomal storage disorder. This prospective, multi-center, multinational longitudinal study aimed to characterize the clinical features of chronic forms of ASMD and disease burden over time in children and adults. Results Fifty-nine patients (31 males/28 females) ranging in age from 7 to 64 years with chronic ASMD types A/B and B and at least two disease symptoms participated from 5 countries. Disease characteristics were assessed at baseline, after 1 year, and at the final visit (ranging from 4.5 to 11 years). Thirty patients (51%) were 10% from baseline to the final visit. Nine patients died (15%), eight of causes related to ASMD (most commonly pneumonia); of these eight patients, five (63%) had symptom onset at or before age 2. Overall, six of the nine deaths occurred before age 50 with three occurring before age 20. Individuals with either severe splenomegaly or prior splenectomy were ten times more likely to have died during the follow-up period than those with smaller or intact spleens (odds ratio 10.29, 95% CI 1.7, 62.7). Most children had growth deficits that persisted into adulthood. Conclusions This study provides important information about the natural history of chronic ASMD and provides a longitudinal view of the spectrum of disease manifestations and major morbidities in children and adults and supports the selection of clinically meaningful endpoints in therapeutic trials.

Background: There are more than 7000 rare diseases, most of which have no specific treatment. Disease profiles, such as prevalence and natural history, among the population of a specific country are essential in determining for which disease to research and develop drugs. In Japan, disease profiles of fewer than 2000 rare diseases, called Nanbyo, have been investigated. However, non-Nanbyo rare diseases remain largely uninvestigated. Accordingly, we revealed the prevalence and natural history of rare diseases among the Japanese population. This cross-disease study is the first to analyze rare-disease epidemiology in Japan with high accuracy, disease coverage, and granularity.Method: We applied for permission to use the National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB), which covered 99.9% of public health insurance claims from hospitals and 97.9% from clinics as of May 2015. Then, we obtained 10 years of data on the number of patients of approx. 4500 rare diseases, by sex and age. We translated disease names and established correspondences between rare diseases in NDB and those in Orphanet. Accordingly, we compared the prevalence and natural history between them.Results: About 3000 diseases in NDB are included in Orphanet and other medical databases. The data indicates that even if the Nanbyo systems do not cover a rare disease, its patients survive in many cases. Regarding natural history, genetic diseases tend to be diagnosed later in Japan than in the West. The data shown in this research are available in the Additional file 1 and the website of NanbyoData.Conclusions: Our research revealed the basic epidemiology and natural history of Japanese patients with some rare diseases using a health insurance claims database. The results imply that the coverage of the present Nanbyo systems is inadequate for rare diseases. Therefore, fundamental reform might be needed to reduce unfairness between rare diseases. Most diseases in Japan follow a tendency of natural history similar to those reported in Orphanet. However, some are detected later, partly because fewer clinical genetic tests are available in Japan than in the West. Finally, we hope that our data and analysis accelerate drug discovery for rare diseases in Japan. [ABSTRACT FROM AUTHOR]

Background: The natural history and genotype-phenotype correlation of Pelizaeus-Merzbacher disease (PMD) of Chinese patients has been rarely reported.Method: Patients who met the criteria for PMD were enrolled in our study. Genomic analysis was conducted by multiplex ligation probe amplification (MLPA) and Sanger or whole-exome sequencing (WES). Natural history differences and genotype-phenotype correlations were analyzed.Result: A total of 111 patients were enrolled in our follow-up study. The median follow-up interval was 53 m (1185). Among PMD patients, developmental delay was the most common sign, and nystagmus and hypotonia were the most common initial symptoms observed. A total of 78.4% of the patients were able to control their head, and 72.1% could speak words. However, few of the patients could stand (9.0%) or walk (4.5%) by themselves. Nystagmus improved in more than half of the patients, and hypotonia sometimes deteriorated to movement disorders. More PLP1 point mutations patients were categorized into severe group, while more patients with PLP1 duplications were categorized into mild group (p < 0.001). Compared to patients in mild groups, those in the severe group had earlier disease onset and had acquired fewer skills at a later age.Conclusion: PMD patients have early disease onset with nystagmus and hypotonia followed by decreased nystagmus and movement disorders, such as spasticit. Patients with PLP1 duplication were more likely to be categorized into the mild group, whereas patients with point mutations were more likely to be categorized into the severe group. [ABSTRACT FROM AUTHOR]

Background: MPS IIIA is a rare, degenerative pediatric genetic disease characterized by symptoms impacting cognition, mobility and behavior; the mean age of death is around 15 years of age. Currently, there are no approved therapies for MPS IIIA.Methods: A two-year, multi-center, prospective, descriptive cohort study was conducted to document the natural history course of MPS IIIA. In the context of this study, semi-structured interviews were performed with parents of children at study entry and one year later. Interview transcripts were analyzed using thematic analysis methods to identity concepts of interest to children and parents, identify what factors impacted parents' burden the most, and develop qualitatively-derived disease severity stages. Children were sorted into these stages according to the symptoms their parents described at the entry interview. This sorting was compared quantitatively to the sorting of children at baseline according to the child's calendar age and their BSID development quotient (DQ).Results: 22 parents in France, Germany, the Netherlands and the UK were interviewed. Children ranged in age from 28 to 105 months (mean 61.4 months). The conceptual models for children's symptoms and impacts and parents' impacts provided a detailed and comprehensive picture of what it is like for children of various ages and their parents to live with MPS IIIA. Four factors were identified as mediating the burden perceived by parents: state support, family support, time since diagnosis, and parent coping strategy. Four disease stages were developed, accounting for both the presence and the severity of MPS IIIA symptoms. The comparison of children's sorting into these stages with the BSID DQ and the child's calendar age showed strong statistical associations.Conclusions: The findings of this qualitative research embedded in a natural history study add to the current understanding of MPS IIIA as a complex disease that impacts every aspect of the lives of children and their families. This study demonstrates the unique potential of mixed methods research in rare diseases to address some of the current limitations of more traditional quantitative approaches by providing an individualized, detailed understanding of the patient experience. [ABSTRACT FROM AUTHOR]

Background: Respiratory complications are the most important cause of morbidity and mortality in spinal muscular atrophy (SMA). Respiratory muscle weakness results in impaired cough, recurrent respiratory tract infections and eventually can cause respiratory failure. We assessed longitudinal patterns of respiratory muscle strength in a national cohort of treatment-naïve children and adults with SMA, hypothesizing a continued decline throughout life.Methods: We measured maximal expiratory and inspiratory pressure (PEmax and PImax), Sniff Nasal inspiratory pressure (SNIP), peak expiratory flow (PEF), and peak cough flow (PCF) in treatment-naïve patients with SMA. We used mixed-models to analyze natural history patterns.Results: We included 2172 measurements of respiratory muscle function from 80 treatment-naïve patients with SMA types 1c-3b. All outcomes were lower in the more severe phenotypes. Significant differences in PEF were present between SMA types from early ages onwards. PEF decline was linear (1-2%/year). PEF reached values below 80% during early childhood in types 1c-2, and during adolescence in type 3a. PEmax and PImax were severely lowered in most patients throughout life, with PEmax values abnormally low (i.e. < 80 cmH2O) in virtually all patients. The PEmax/PImax ratio was < 1 throughout life in all SMA types, indicating that expiratory muscles were most affected. All but SMA type 3b patients had a lowered PCF. Patients with types 2b and 3a had PCF levels between 160 and 270 L/min, those with type 2a around 160 L/min and patients with type 1c well below 160 L/min. Finally, SNIP was low in nearly all patients, most pronounced in more severely affected patients.Conclusions: There are clear differences in respiratory muscle strength and its progressive decline between SMA types. We observed lower outcomes in more severe SMA types. Particularly PEF may be a suitable outcome measure for the follow-up of respiratory strength in patients with SMA. PEF declines in a rather linear pattern in all SMA types, with clear differences at baseline. These natural history data may serve as a reference for longer-term treatment efficacy assessments. [ABSTRACT FROM AUTHOR]