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BackgroundThe mucopolysaccharidoses (MPSs) are lysosomal storage disorders associated with progressive multi-organ and skeletal abnormalities. Clinical manifestations can affect each of the five senses: hearing, vision, smell, taste, and touch. On 24-26 May 2018, 46 specialists with expertise in managing symptoms of MPS and experts specialized in evaluating and managing impairments in each one of the five senses gathered in Lisbon, Portugal at the "MPS & the five senses" meeting to discuss how loss of one or multiple senses can affect activities of daily living (ADL) and quality of life (QoL) in MPS patients and best practices in evaluating and managing the loss of senses in these individuals. The meeting confirmed that MPS can affect the senses considerably, but how these impairments affect ADL and overall QoL from a patient's perspective remains unclear. A better insight may be achieved by prospectively collecting patient-reported outcome (PRO) data internationally in a standardized way, using a standard battery of tools. To identify relevant PRO tools, a systematic literature review and a selection of existing published questionnaires, focused on adults with no intellectual delay, were performed after the meeting. The search strategy identified 33 PRO tools for hearing, 30 for speech, 125 for vision, 49 for touch (including pain and upper limb function), and 15 for smell/taste. A further selection was made based on several criteria, including applicability/relevance for MPS, applicability in different countries (languages)/cultures, availability in English, ease of use, validation, and normative data, resulting in a final set of 11 tools. In addition to these sense-specific PRO tools, a general QoL tool, the EuroQol (EQ)-5D-5 L, was selected to assess overall QoL and reveal coping behaviors.Short conclusionMPS can affect each of the five senses, but current knowledge on the impact of sense impairments on QoL/ADL in MPS patients remains limited. Collection of data in a standardized fashion using sense-specific patient-reported outcome tools and a general QoL tool may fill the current knowledge gap.

IntroductionMucopolysaccharidosis (MPS) IVA or Morquio A syndrome is an autosomal recessive lysosomal storage disorder (LSD) caused by deficiency of the N-acetylgalactosamine-6-sulfatase (GALNS) enzyme, which impairs lysosomal degradation of keratan sulphate and chondroitin-6-sulphate. The multiple clinical manifestations of MPS IVA present numerous challenges for management and necessitate the need for individualised treatment. Although treatment guidelines are available, the methodology used to develop this guidance has come under increased scrutiny. This programme was conducted to provide evidence-based, expert-agreed recommendations to optimise management of MPS IVA.MethodsTwenty six international healthcare professionals across multiple disciplines, with expertise in managing MPS IVA, and three patient advocates formed the Steering Committee (SC) and contributed to the development of this guidance. Representatives from six Patient Advocacy Groups (PAGs) were interviewed to gain insights on patient perspectives. A modified-Delphi methodology was used to demonstrate consensus among a wider group of healthcare professionals with experience managing patients with MPS IVA and the manuscript was evaluated against the validated Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument by three independent reviewers.ResultsA total of 87 guidance statements were developed covering five domains: (1) general management principles; (2) recommended routine monitoring and assessments; (3) disease-modifying interventions (enzyme replacement therapy [ERT] and haematopoietic stem cell transplantation [HSCT]); (4) interventions to support respiratory and sleep disorders; (5) anaesthetics and surgical interventions (including spinal, limb, ophthalmic, cardio-thoracic and ear-nose-throat [ENT] surgeries). Consensus was reached on all statements after two rounds of voting. The overall guideline AGREE II assessment score obtained for the development of the guidance was 5.3/7 (where 1 represents the lowest quality and 7 represents the highest quality of guidance).ConclusionThis manuscript provides evidence- and consensus-based recommendations for the management of patients with MPS IVA and is for use by healthcare professionals that manage the holistic care of patients with the intention to improve clinical- and patient-reported outcomes and enhance patient quality of life. It is recognised that the guidance provided represents a point in time and further research is required to address current knowledge and evidence gaps.

IntroductionMucopolysaccharidosis (MPS) VI or Maroteaux-Lamy syndrome (253200) is an autosomal recessive lysosomal storage disorder caused by deficiency in N-acetylgalactosamine-4-sulfatase (arylsulfatase B). The heterogeneity and progressive nature of MPS VI necessitates a multidisciplinary team approach and there is a need for robust guidance to achieve optimal management. This programme was convened to develop evidence-based, expert-agreed recommendations for the general principles of management, routine monitoring requirements and the use of medical and surgical interventions in patients with MPS VI.Methods26 international healthcare professionals from various disciplines, all with expertise in managing MPS VI, and three patient advocates formed the Steering Committee group (SC) and contributed to the development of this guidance. Members from six Patient Advocacy Groups (PAGs) acted as advisors and attended interviews to ensure representation of the patient perspective. A modified-Delphi methodology was used to demonstrate consensus among a wider group of healthcare professionals with expertise and experience managing patients with MPS VI and the manuscript has been evaluated against the validated Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument by three independent reviewers.ResultsA total of 93 guidance statements were developed covering five domains: (1) general management principles; (2) recommended routine monitoring and assessments; (3) enzyme replacement therapy (ERT) and hematopoietic stem cell transplantation (HSCT); (4) interventions to support respiratory and sleep disorders; (5) anaesthetics and surgical interventions. Consensus was reached on all statements after two rounds of voting. The greatest challenges faced by patients as relayed by consultation with PAGs were deficits in endurance, dexterity, hearing, vision and respiratory function. The overall guideline AGREE II assessment score obtained for the development of the guidance was 5.3/7 (where 1 represents the lowest quality and 7 represents the highest quality of guidance).ConclusionThis manuscript provides evidence- and consensus-based recommendations for the management of patients with MPS VI and is for use by healthcare professionals that manage the holistic care of patients with the intention to improve clinical- and patient-reported outcomes and enhance patient quality of life. It is recognised that the guidance provided represents a point in time and further research is required to address current knowledge and evidence gaps.

Severe mucopolysaccharidosis type II (MPS-II) patients present with progressive mental impairment and reduced life expectancy. While current available treatment cannot cross the blood–brain barrier, the enzyme replacement therapy with pabinafusp alfa (a recombinant iduronate-2-sulfatase fused to an antihuman transferrin receptor antibody) was designed to penetrate it using transferrin receptor-mediated transcytosis. In this cross-sectional retrospective study, we aimed to report the impact of this new therapy using patient-reported outcomes. Data were collected using standardized questionnaire replied by patients or their caregivers (as proxies). Nine patients received intravenous administration of pabinafusp alfa for at least 104 weeks. All patient showed improvements in behavior (mainly aggressiveness), speech, motor ability, muscle strength, facial expression, breathing, and cognitive skills. Gait improvement was also found in 78% of participants. Caregivers also reported improvements in emotion demonstration as ability to smile, establish eye contact, and give hugs. Collectively, our results indicate a positive impact of pabinafusp alfa on quality of life of individuals with MPS-II and their relatives/caregivers. Future studies are warranted to elucidate the mechanisms underlying these beneficial effects. [ABSTRACT FROM AUTHOR]

Totally implantable vascular access devices (TIVADs) are commonly used in conjunction with enzyme replacement therapy (ERT) for lysosomal storage disorders (LSDs). This case series describes potential complications associated with long-term TIVAD use, such as compromise of skin integrity, infection, or port failures. Best practices and skilled specialists are essential for minimizing complications from long-term TIVAD use for ERT.

Mucopolysaccharidosis (MPS) is a group of rare metabolic diseases associated with reduced life expectancy and a substantial unmet medical need. Immunomodulatory drugs could be a relevant treatment approach for MPS patients, although they are not licensed for this population. Therefore, we aim to provide evidence justifying fast access to innovative individual treatment trials (ITTs) with immunomodulators and a high-quality evaluation of drug effects by implementing a risk–benefit model for MPS. The iterative methodology of our developed decision analysis framework (DAF) consists of the following steps: (i) a comprehensive literature analysis on promising treatment targets and immunomodulators for MPS; (ii) a quantitative risk–benefit assessment (RBA) of selected molecules; and (iii) allocation phenotypic profiles and a quantitative assessment. These steps allow for the personalized use of the model and are in accordance with expert and patient representatives. The following four promising immunomodulators were identified: adalimumab, abatacept, anakinra, and cladribine. An improvement in mobility is most likely with adalimumab, while anakinra might be the treatment of choice for patients with neurocognitive involvement. Nevertheless, a RBA should always be completed on an individual basis. Our evidence-based DAF model for ITTs directly addresses the substantial unmet medical need in MPS and characterizes a first approach toward precision medicine with immunomodulatory drugs. [ABSTRACT FROM AUTHOR]

Mucopolysaccharidosis VII (MPS VII, Sly syndrome) is an ultra-rare lysosomal disease caused by a deficiency of the enzyme β-glucuronidase (GUS). The diagnosis is suspected based on a range of symptoms that are common to many other MPS types, and it is confirmed through biochemical and molecular studies. Besides supportive treatment, current and emerging treatments include enzyme replacement therapy, hematopoietic stem cell transplantation, and gene therapy. This review summarizes the clinical manifestations, diagnosis, and emerging treatments for MPS VII. [ABSTRACT FROM AUTHOR]

Sanfilippo syndrome is a group of rare, complex, and progressive neurodegenerative lysosomal storage disorders that is characterized by childhood dementia. The clinical management of patients with progressive neurological decline and multisystem involvement requires a multidisciplinary team with experience in the management of neurodegenerative disorders. Best practice guidelines for the clinical management of patients with these types of rare disorders are critical to ensure prompt diagnosis and initiation of appropriate care. However, there are no published standard global clinical care guidelines for patients with Sanfilippo syndrome. To address this, a literature review was conducted to evaluate the current evidence base and to identify evidence gaps. The findings were reviewed by an international steering committee composed of clinical experts with extensive experience in managing patients with Sanfilippo syndrome. The goal was to create a consensus set of basic clinical guidelines that will be accessible to and informed by clinicians globally, as well as providing a practical resource for families to share with their local care team who may not have experience with this rare disease. This review distills 178 guideline statements into an easily digestible document that provides evidence-based, expert-led recommendations for how to approach common management challenges and appropriate monitoring schedules in the care of patients with Sanfilippo syndrome. [ABSTRACT FROM AUTHOR]

The article titled "An Innovative Tool for Evidence-Based, Personalized Treatment Trials in Mucopolysaccharidosis" has been retracted by the journal Pharmaceutics. The retraction was made due to concerns about the use of unpublished trial data without permission and potential inaccuracies in the data. The investigation confirmed that the authors did not have appropriate permission to use the trial data and that there were errors in the presentation of the data. The authors of the article have agreed to the retraction. [Extracted from the article]

Objective: Early diagnosis and treatment initiation are important factors for successful treatment of mucopolysaccharidosis type I (MPS I). The purpose of this observational study was to assess whether age at diagnosis and time to first treatment for individuals with MPS I have improved over the last 15 years.Study Design: Data from the MPS I Registry (NCT00144794) for individuals with attenuated or severe disease who initiated therapy with laronidase enzyme replacement therapy (ERT) and/or hematopoietic stem cell transplantation (HSCT) between 1 January 2003 and 31 December 2017 were included.Results: Data were available for 740 individuals with attenuated (n=291) or severe (n=424) MPS I (unknown n=25). Median age at diagnosis for attenuated disease did not change over time and ranged between 4.5 and 6 years of age while the median duration from diagnosis to first ERT decreased from 5.6 years before/during 2004 to 2.4 months in 2014-2017. For severe MPS I treated with HSCT, median age at diagnosis was less than 1 year and median time to first treatment was less than 3 months throughout the 15-year observation period.Conclusions: Times to diagnosis and HSCT initiation for individuals with severe MPS I were consistent over time. For individuals with attenuated MPS I, the time to ERT initiation after diagnosis has improved substantially in the last 15 years, but median age at diagnosis has not improved. Efforts to improve early diagnosis in attenuated MPS I are needed to ensure that patients receive appropriate treatment at the optimal time. [ABSTRACT FROM AUTHOR]

Background: Mucopolysaccharidosis type VII (MPS VII), also known as Sly syndrome, caused by deficiency of the lysosomal enzyme β-glucuronidase, is an ultra-rare disorder with scarce epidemiological data and few publications about natural history and clinical spectrum.Methods: We conducted a case series report which included retrospective data from all MPS VII patients diagnosed through the "MPS Brazil Network" who were known to be alive in 2020 in Brazil (N = 13). Clinical data were obtained from a review of the medical records and descriptive statistics and variables were summarized using counts and percentages of the total population.Results: The majority of the patients were from the Northeast region of Brazil. Among the signs and symptoms that raised the clinical suspicion of MPS, coarse face was the most frequent; 58% of the patients had a history of non-immune hydrops fetalis. All the subjects presented short neck and trunk. The majority presented typical phenotypical signs of MPS disorders. They all presented neurodevelopmental delay and cognitive impairment. About half of this cohort had knees deformities. Dysostosis multiplex was identified in almost all patients and cardiomyopathy was less frequent than observed in other types of MPSs. The mean age at diagnosis was 5 years, ranging from 1 to 14 years. Almost all patients (12/13) were homozygous for the c.526C>T (p.Leu176Phe) mutation. A novel variant of the GUSB gene was found, the c.875T>C (p.Leu292Pro), in a compound heterozygous with the c.526C>T (p.Leu176Phe) variant.Conclusions: This case series is the biggest data collection of MPS VII patients alive in Latin America. The overall clinical picture of the MPS VII patients is very similar to other MPS disorders, including a spectrum of severity and delayed diagnosis. [ABSTRACT FROM AUTHOR]

Background: Mucopolysaccharidoses (MPS) are a group of rare illnesses caused by deficient activity of enzymes required for degradation of glycosaminoglycans (GAGs). Each type of MPS is caused by mutations in one of the genes that encode the 11 acid hydrolases involved in this degradation process, which are present in the lysosomes. Progressive accumulation of GAGs in the lysosomes result in cellular dysfunction and multisystemic clinical signs, with consequent decrease in quality of life and lifespan of the affected patients. The objective of the present work is to report a case of MPS type I in a dog. Case: A mixed-breed male dog of approximately 2-month-old weighing 2.5 kg was referred to Hospital Veterinário de Uberaba with a distended abdomen. At the clinical examination, the patient exhibited a regular nutritional status, pale mucous membranes, 7% dehydration, an arterial pulse rate of 120 beats per minute, a respiratory rate of 40 breaths per minute, and a heart rate of 120 beats per minute. There were increased abdominal volume and tension, and hepatosplenomegaly. The abdominal percussion exam produced a dull tone. Additional findings included muscular atrophy, increased volume in the metaphyseal areas of the thoracic and pelvic limbs, valgus limb deformity in the thoracic limbs, and instability of the hip joint. Radiographic examination revealed a series of bone alterations such as reduced vertebral bodies, a generalized decrease in radiopacity, thin cortical areas in long bones, narrowing of the pelvic canal, and marked deformation and irregularities in acetabular and epiphyseal (both proximal and distal) areas of the femurs and tibias. Ankylosis of the tibiotarsal and tarsometatarsal joints was also observed. There was also loss of trabecular structure and irregularities on the surfaces of all epiphyses of the bones, epiphyseal lines markedly open, and bones that were shorter and thicker than normal. The suspected diagnoses were pseudoachondroplasia and mucopolysaccharidosis. In view of the clinical and radiographic findings, tests were performed to investigate the clinical suspicion of MPS. Consequently, qualitative and quantitative tests of GAGs in the urine, as well as a blood enzymatic essay, were requested; results confirmed the diagnosis of MPS type I. Intensive treatment allowed the patient to reach adulthood. Whenever new clinical signs emerged, they were treated palliatively. As the disease became more severe, the patient died at the age of 3 years. Discussion: Mucopolysaccharidosis type I is a rare disease that exhibits variable clinical signs and for which there is no specific treatment in dogs; these characteristics hinder diagnosis and treatment of patients as the one described in this report. The major clinical signs observed in this case are in agreement with those reported in the literature, according to which the disease can cause severe alterations such as bone defects, increased volume and deformities in the joints of the limbs, corneal opacity, and enlargement of abdominal organs such as the liver and spleen. In considering diagnostic methods for MPS, the main screening test is quantification of GAGs in the urine. The confirmatory test for MPS consists of analysis of the activity of specific lysosomal enzymes in a blood sample; this test allowed the establishment of a diagnosis in this case. Enzyme replacement therapy, in which a recombinant enzyme is used, have yielded good results in humans and dogs. However, this treatment does not cure the disease - it only attenuates the clinical signs and enables the patient to reach adulthood. Access to enzyme replacement therapy was not possible in the present case. As a conclusion, MPS should be included in the differential diagnosis of developmental diseases in puppies. This highlights the importance of further studies and reports on this disease. [ABSTRACT FROM AUTHOR]

Mucopolysaccharidosis type I (MPS I) is a rare autosomal recessive disorder resulting from pathogenic variants in the α‐L‐iduronidase (IDUA) gene. Clinical phenotypes range from severe (Hurler syndrome) to attenuated (Hurler‐Scheie and Scheie syndromes) and vary in age of onset, severity, and rate of progression. Defining the phenotype at diagnosis is essential for disease management. To date, no systematic analysis of genotype‐phenotype correlation in large MPS I cohorts have been performed. Understanding genotype‐phenotype is critical now that newborn screening for MPS I is being implemented. Data from 538 patients from the MPS I Registry (380 severe, 158 attenuated) who had 2 IDUA alleles identified were examined. In the 1076 alleles identified, 148 pathogenic variants were reported; of those, 75 were unique. Of the 538 genotypes, 147 (27%) were unique; 40% of patients with attenuated and 22% of patients with severe MPS I had unique genotypes. About 67.6% of severe patients had genotypes where both variants identified are predicted to severely disrupt protein/gene function and 96.1% of attenuated patients had at least one missense or intronic variant. This dataset illustrates a close genotype/phenotype correlation in MPS I but the presence of unique IDUA missense variants remains a challenge for disease prediction. [ABSTRACT FROM AUTHOR]

Mucopolysaccharidosis type IIIC (MPSIIIC) is a severe, rare autosomal recessive disorder caused by variants in the heparan‐α‐glucosaminide N‐acetyltransferase (HGSNAT) gene which result in lysosomal accumulation of heparan sulfate. We analyzed clinical presentation, molecular defects and their haplotype context in 78 (27 novel) MPSIIIC cases from 22 countries, the largest group studied so far. We describe for the first time disease‐causing variants in the patients from Brazil, Algeria, Azerbaijan, and Iran, and extend their spectrum within Canada, Colombia, Turkey, and the USA. Six variants are novel: two missense, c.773A>T/p.N258I and c.1267G>T/p.G423W, a nonsense c.164T>A/p.L55*, a splice‐site mutation c.494−1G>A/p.[P165_L187delinsQSCYVTQAGVRWHHLGSLQALPPGFTPFSYLSLLSSWNC,P165fs], a deletion c.1348delG/p.(D450fs) and an insertion c.1479dupA/p.(Leu494fs). The missense HGSNAT variants lacked lysosomal targeting, enzymatic activity, and likely the correct folding. The haplotype analysis identified founder mutations, p.N258I, c.525dupT, and p.L55* in the Brazilian state of Paraiba, c.493+1G>A in Eastern Canada/Quebec, p.A489E in the USA, p.R384* in Poland, p.R344C and p.S518F in the Netherlands and suggested that variants c.525dupT, c.372−2G>A, and c.234+1G>A present in cis with c.564‐98T>C and c.710C>A rare single‐nucleotide polymorphisms, have been introduced by Portuguese settlers in Brazil. Altogether, our results provide insights into the origin, migration roots and founder effects of HGSNAT disease‐causing variants, and reveal the evolutionary history of MPSIIIC. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to raise awareness of the need for research and appropriate guidelines for managing spinal cord issues in adult patients with mucopolysaccharidosis (MPS) and transition of these patients from pediatric to adult care.Methods: Pediatric/adult neurosurgeons, orthopedic spine surgeons, and treating physicians with expertise in metabolic disorders and spinal cord issues were invited to complete a survey to assess their experience with spinal cord problems in MPS and their opinion on transitioning routes from pediatric to adult care.Results: Twenty specialists completed the survey; 16 had treated spinal cord issues in patients with MPS. Foramen magnum and cervical stenosis (87%), atlanto-axial instability (67%), and lumbar spine instability (33%) were the main spinal cord issues encountered; 28% had treated adult patients for one or more spinal cord issues. In 40% of cases, this concerned an intervention or procedures performed during childhood. The main specialist responsible for the care of adult patients with MPS differed considerably between institutions and included both pediatric and adult specialists (30% pediatric neurosurgeons, 10% pediatric spine orthopedic surgeons, 30% adult spine neurosurgeons, 20% general adult surgeons). The preferred option (> 50%) for the transition of care was an interdisciplinary team of pediatric and adult specialists.Conclusions: Further work needs to be done to address problems of managing spinal cord issues in adult patients with MPS. Currently, the responsibility for the care of patients with MPS with spinal cord issues is inconsistent. The best strategy for transitioning these patients from pediatric to adult care is likely an interdisciplinary approach. [ABSTRACT FROM AUTHOR]

Objective: Mucopolysaccharidosis (MPS) VI is a rare disorder caused by an autosomal recessive mutation in the short arm of chromosome 5 (5q12-13) leading to an N-acetylgalactosamine-sulfatase lysosomal enzyme deficiency and numerous systemic clinical changes. The oral and maxillofacial complex may exhibit tooth eruption anomalies, macroglossia, gingival hypertrophy, mouth breathing, increased lower facial height, open bite, retrognathia, and progressive TMJ arthrosis. This report describes craniofacial growth changes in two MPS VI patients, sisters and daughters of outbred parents, who were longitudinally monitored from 11 to 15 years of age.Study Design: Skull lateral teleradiography and cephalometric tracings were performed. The measurements were assessed in the anteroposterior and vertical directions based on protocols by McNamara and Usp/Unicamp and compared to the normal reported ranges.Results: A similar skeletal class III malocclusion was observed in both patients. The jaw was retruded, the anterior skull base decreased, and the mandibular body was normal or larger than normal. The vertical growth direction differed between the patients; one was hyperdivergent, while the other was hypodivergent.Conclusions: By understanding the craniofacial growth changes in MPS VI patients, new treatment options may be developed for affected patients. [ABSTRACT FROM AUTHOR]

Background: Very little is known about the incidence and prevalence of hydrocephalus in patients with mucopolysaccharidoses (MPS). The biggest challenge is to distinguish communicating hydrocephalus from ventricular dilatation secondary to brain atrophy, because both conditions share common clinical and neuroradiological features. The main purpose of this study is to assess the relationship between ventriculomegaly, brain and cerebrospinal fluid (CSF) volumes, aqueductal and cervical CSF flows, and CSF opening pressure in MPS patients, and to provide potential biomarkers for abnormal CSF circulation. Methods: Forty-three MPS patients (12 MPS I, 15 MPS II, 5 MPS III, 9 MPS IV A and 2 MPS VI) performed clinical and developmental tests, and T1, T2, FLAIR and phase-contrast magnetic resonance imaging (MRI) followed by a lumbar puncture with the CSF opening pressure assessment. For the analysis of MRI variables, we measured the brain and CSF volumes, white matter (WM) lesion load, Evans' index, third ventricle width, callosal angle, dilated perivascular spaces (PVS), craniocervical junction stenosis, aqueductal and cervical CSF stroke volumes, and CSF glycosaminoglycans concentration. Results: All the scores used to assess the supratentorial ventricles enlargement and the ventricular CSF volume presented a moderate correlation with the aqueductal CSF stroke volume (ACSV). The CSF opening pressure did not correlate either with the three measures of ventriculomegaly, or the ventricular CSF volume, or with the ACSV. Dilated PVS showed a significant association with the ventriculomegaly, ventricular CSF volume and elevated ACSV. Conclusions: In MPS patients ventriculomegaly is associated with a severe phenotype, increased cognitive decline, WM lesion severity and enlarged PVS. The authors have shown that there are associations between CSF flow measurements and measurements related to CSF volumetrics. There was also an association of volumetric measurements with the degree of dilated PVS. [ABSTRACT FROM AUTHOR]

Background: Mucopolysaccharidosis type IVA, also known as Morquio A or MPS IV A, is an autosomal recessive disease caused by the deficiency of the lysosomal enzyme N-acetylgalactosamine-6-sulfate sulfatase (GALNS). The loss of GALNS activity leads to the impaired breakdown of glycosaminoglycans (GAGs) keratan sulfate and chondroitin- 6-sulfate. The accumulation of GAGs results in multiple organ damage. The accurate and early diagnosis of this disorder helps enhance the effectiveness of the treatment. The present study uses a pre-designed protocol for testing GALNS activity in the leukocytes of Iranian patients with MPS IV A and their parents and compares it with healthy controls. Methods: Patients with MPS IVA previously diagnosed through the measurement of enzyme activity or genetic analysis entered the study. Leukocytes were obtained from the heparinized blood of the participants. The GALNS activity was measured by a fluorometric method using 4-methylumbelliferyl-β-D-galactoside-6-sulfate (4MU-G6S) as the substrate and proper buffer solutions and calibrators. Results: The GALNS activity (nmol/17 h/mg protein) was reported as 0-7.4 in the MPSIV A patients, as 19.85-93.7 in their parents and as 38.4-164 in the healthy controls. Statistically significant differences were observed between the three groups in terms of enzyme activity. There were no significant differences in enzyme activity by age. The female subjects in both the patient and parents groups showed lower enzyme activity compared to the male subjects. Conclusion: The fluorometric method was validated for the measurement of GALNS activity in leukocyte samples and identifying Iranian patients with MPS IV A. [ABSTRACT FROM AUTHOR]

Introduction: The precise incidence of hydrocephalus in patients with mucopolysaccharidoses (MPS) is hard to determine, because the condition lacks a formal, consensus-based definition. The diagnosis of hydrocephalus depends on symptom profile, presence of neuroimaging features, and the outcome of diagnostic tests. Although numerous techniques are used to identify MPS patients who are most likely to have hydrocephalus and respond to treatment, no definitive method exists to prove diagnosis. Purpose: The authors propose an algorithm to aid in the diagnosis and management of hydrocephalus in MPS patients. Conclusions: The theory of venous hypertension associated with the morphological changes in the skull base and craniocervical junction indicate the need for future neuroimaging studies including cerebrospinal fluid (CSF) and venous flow measurements to monitor hydrocephalus progression and select therapeutic interventions in MPS patients. Preoperative planning should also be based on the increased risk of intraoperative and postoperative hemorrhagic complications. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to quantify glycosaminoglycans (GAGs) in amniotic fluid (AF) from an MPS VII fetus compared with age-matched fetuses obtained from normal pregnancies.Method: Disaccharides were measured by liquid chromatography tandem mass spectrometry, compared to age-matched controls. Enzyme assay was performed in AF supernatant or cultured amniocytes. GUSB was analyzed by next generation sequencing using Ion Torrent Personal Genome Machine with a customized panel.Results: No activity of β-glucuronidase was detected in fetal cells. The pregnancy was spontaneously terminated in the third trimester. Genetic studies identified a homozygous mutation of p.N379D (c.1135A > G) in the GUSB gene. Liquid chromatography tandem mass spectrometry showed that chondroitin sulfate, dermatan sulfate, heparan sulfate, and keratan sulfate levels were markedly increased in the MPS VII AF, compared to those in age-matched control AF (dermatan sulfate, heparan sulfate, and chondroitin-6-sulfate more than 10 × than age-matched controls; chondroitin-4-sulfate and keratan sulfate more than 3 times higher).Conclusion: This is the first report of specific GAG analysis in AF from an MPS VII fetus, indicating that GAG elevation in AF occurs by 21 weeks of gestation and could be an additional tool for prenatal diagnosis of MPS VII and potentially other MPS types. © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Background Mucopolysaccharidosis VII (MPS VII) is an ultra-rare disease characterised by the deficiency of β-glucuronidase (GUS). Patients' phenotypes vary from severe forms with hydrops fetalis, skeletal dysplasia and mental retardation to milder forms with fewer manifestations and mild skeletal abnormalities. Accurate assessments on the frequency and clinical characteristics of the disease have been scarce. The aim of this study was to collect such data. Methods We have conducted a survey of physicians to document the medical history of patients with MPS VII. The survey included anonymous information on patient demographics, family history, mode of diagnosis, age of onset, signs and symptoms, severity, management, clinical features and natural progression of the disease. Results We collected information on 56 patients from 11 countries. Patients with MPS VII were classified based on their phenotype into three different groups: (1) neonatal non-immune hydrops fetalis (NIHF) (n=10), (2) Infantile or adolescent form with history of hydrops fetalis (n=13) and (3) Infantile or adolescent form without known hydrops fetalis (n=33). Thirteen patients with MPS VII who had the infantile form with history of hydrops fetalis and survived childhood, had a wide range of clinical manifestations from mild to severe. Five patients underwent bone marrow transplantation and one patient underwent enzyme replacement therapy with recombinant human GUS. Conclusions MPS VII is a pan-ethnic inherited lysosomal storage disease with considerable phenotypical heterogeneity. Most patients have short stature, skeletal dysplasia, hepatosplenomegaly, hernias, cardiac involvement, pulmonary insufficiency and cognitive impairment. In these respects it resembles MPS I and MPS II. In MPS VII, however, one unique and distinguishing clinical feature is the unexpectedly high proportion of patients (41%) that had a history of NIHF. Presence of NIHF does not, by itself, predict the eventual severity of the clinical course, if the patient survives infancy. [ABSTRACT FROM AUTHOR]

Background: Enzyme replacement therapy (ERT) with laronidase (recombinant human α-L-iduronidase, Aldurazyme®) is indicated for non-neurological signs and symptoms of mucopolysaccharidosis type I (MPS I). The approved laronidase dose regimen is weekly infusions of 0.58mg/kg, however, patients and caregivers may have difficulty complying with the weekly regimen. We examined clinical outcomes, tolerability, compliance, and satisfaction in a series of patients who switched to every other week infusions.Methods: This multinational, retrospective, chart review case series analyzed data from 20 patients who had undergone ERT with laronidase 0.58mg/kg weekly for more than one year, and who then switched to 1.2mg/kg every other week.Results: The majority of patients had attenuated MPS I phenotypes (9 with Hurler-Scheie and 8 with Scheie syndromes) and 3 patients had severe MPS I (Hurler syndrome). Most patients presented with organomegaly (17/20), umbilical and/or inguinal hernia (16/20), cardiac abnormalities (17/20), musculoskeletal abnormalities (19/20), and neurological and/or developmental deficits (15/20). Following laronidase treatment, signs stabilized or improved. No deterioration or reversal of clinical outcome was noted in any patient who switched from the weekly dose of 0.58mg.kg to 1.2mg/kg every other week. There were no safety issues during the duration of every other week dosing. Patient compliance and satisfaction with the dosing regimen were greater with every other week dosing than weekly dosing.Conclusions: An alternative dose regimen of 1.2mg/kg laronidase every other week was well tolerated and clinically similar to the standard dose for patients who were stabilized with weekly 0.58 mg/kg for one year or more. When an individualized approach to laronidase therapy is necessary, every other week dosing may be an alternative for patients with difficulty receiving weekly infusions. [ABSTRACT FROM AUTHOR]

Mucopolysaccharidosis VI (MPS VI) is a very rare autosomal recessive disorder caused by mutations in the ARSB gene, which lead to deficient activity of the lysosomal enzyme ASB. This enzyme is important for the breakdown of the glycosaminoglycans (GAGs) dermatan sulfate and chondroitin sulfate, which accumulate in body tissues and organs of MPS VI patients. The storage of GAGs (especially dermatan sulfate) causes bone dysplasia, joint restriction, organomegaly, heart disease, and corneal clouding, among several other problems, and reduced life span. Despite the fact that most cases are severe, there is a spectrum of severity and some cases are so attenuated that diagnosis is made late in life. Although the analysis of urinary GAGs and/ or the measurement of enzyme activity in dried blood spots are useful screening methods, the diagnosis is based in the demonstration of the enzyme deficiency in leucocytes or fibroblasts, and/or in the identification of pathogenic mutations in the ARSB gene. Specific treatment with enzyme replacement has been available since 2005. It is safe and effective, bringing measurable benefits and increased survival to patients. As several evidences indicate that early initiation of therapy may lead to a better outcome, newborn screening is being considered for this condition, and it is already in place in selected areas where the incidence of MPS VI is increased. However, as enzyme replacement therapy is not curative, associated therapies should be considered, and research on innovative therapies continues. The management of affected patients by a multidisciplinary team with experience in MPS diseases is highly recommended. [ABSTRACT FROM AUTHOR]

Mucopolysaccharidoses ( MPS) are lysosomal storage disorders characterized by mutations in enzymes that degrade glycosaminoglycans ( GAGs). Joint disease is present in most forms of MPS, including MPS I. This work aimed to describe the joint disease progression in the murine model of MPS I. Normal (wild-type) and MPS I mice were sacrificed at different time points (from 2 to 12 months). The knee joints were collected, and haematoxylin-eosin staining was used to evaluate the articular architecture. Safranin-O and Sirius Red staining was used to analyse the proteoglycan and collagen content. Additionally, we analysed the expression of the matrix-degrading metalloproteinases ( MMPs), MMP-2 and MMP-9, using immunohistochemistry. We observed progressive joint alterations from 6 months, including the presence of synovial inflammatory infiltrate, the destruction and thickening of the cartilage extracellular matrix, as well as proteoglycan and collagen depletion. Furthermore, we observed an increase in the expression of MMP-2 and MMP-9, which could conceivably explain the degenerative changes. Our results suggest that the joint disease in MPS I mice may be caused by a degenerative process due to increase in proteases expression, leading to loss of collagen and proteoglycans. These results may guide the development of ancillary therapies for joint disease in MPS I. [ABSTRACT FROM AUTHOR]

Mucopolysaccharidosis II (MPS II), or Hunter syndrome, is an X-linked lysosomal storage disorder caused by a deficiency in the enzyme iduronate-2-sulfatase. Affected patients suffer progressive damage to multiple organ systems and early mortality. Two thirds of patients also manifest cognitive impairment and developmental delays. MPS II can be extremely difficult to diagnose before irreversible organ and tissue damage has occurred because of an insidious onset and the overlap in signs and symptoms with common childhood complaints. This is particularly true of patients without cognitive impairment (attenuated phenotype). Although not curative, early treatment with enzyme replacement therapy before irreversible organ damage has occurred may result in the greatest clinical benefit. Here, the signs, symptoms, and surgical history that should trigger suspicion of MPS II are described, and the diagnostic process is reviewed with a focus on practical considerations and the avoidance of common diagnostic pitfalls. Once a diagnosis is made, multidisciplinary management with an extended team of pediatric specialists is essential and should involve the pediatrician or family practice physician as facilitator and medical home for the patient and family. Conclusion: Because routine newborn screening is not yet available for MPS II, the involvement and awareness of pediatricians, family practice physicians, and pediatric specialists is critical for early identification, diagnosis, and referral in order to help optimize patient outcomes. [ABSTRACT FROM AUTHOR]

Introduction: The mucopolysaccharidoses (MPS) are rare genetic disorders caused by a deficiency in lysosomal enzymes that affect the catabolism of glycosaminoglycans and cause their accumulation, resulting in a multisystemic clinical picture. Their clinical manifestations result in limited ability to perform daily life tasks. Objectives: To evaluate functional capacity and joint range of motion (ROM) in patients with MPS followed at the reference center for lysosomal disorders at Hospital de Clínicas de Porto Alegre, Brazil. Methods: This was a prospective longitudinal study with a convenience sample. The Pediatric Evaluation of Disability Inventory (PEDI) and the Functional Independence Measure (FIM) were used to evaluate functionality and goniometry was used to evaluate ROM at three times (baseline, 6 months, and 12 months after study inclusion). An exploratory analysis was done of the effect of enzyme replacement therapy (ERT) in both variables; thus, patients were divided into Group 1 (patients without ERT), Group 2 (patients on ERT before and after study inclusion), and Group 3 (patients who started ERT after study inclusion). Results: 21 patients were included: 7 in Group 1 (MPS II: 3, MPS III-B: 2, MPS IV-A: 2), 6 in Group 2 (MPS I: 3; MPS VI: 3), and 8 in Group 3 (MPS I: 3, MPS II: 4, MPS VI: 1). A limitation in the mobility of all joints studied was found especially in MPS I, II, and VI. Functionality compromise was also frequent (PEDI=5/7 patients; MIF=9/14 patients), even in individuals with preserved cognition. No correlation was found between the findings of goniometry and the PEDI domains (self-care, mobility, social function). ERT did not seem to significantly change the parameters analyzed. Discussion/conclusion: The compromise of joint mobility and functionality seems to be common in MPS I, II, III-B, IV-A, and VI. This finding is in line with the fact that, although these types of MPS are caused by different genetic defects, they share metabolic routes and physiopathogenic processes and present similar clinical manifestations. The preservation of functionality is an increasing challenge in the treatment of MPS patients, and maintenance of occupational performance should be defined as an objective to be reached by therapies used. Further studies with a greater sample size are necessary in order to verify the effect of ERT in these variables. [ABSTRACT FROM AUTHOR]

Mucopolysaccharidosis type II (MPS II or Hunter syndrome) is a rare, inherited disorder caused by deficiency of the lysosomal enzyme iduronate-2-sulfatase. As a result of this deficiency, glycosaminoglycans accumulate in lysosomes in many tissues, leading to progressive multisystemic disease. The cardiopulmonary and neurological problems associated with MPS II have received considerable attention. Orthopedic manifestations are common but not as well characterized. This study aimed to characterize the prevalence and severity of orthopedic manifestations of MPS II and to determine the relationship of these signs and symptoms with cardiovascular, pulmonary and central nervous system involvement. Orthopedic manifestations of MPS II were studied using cross-sectional data from the Hunter Outcome Survey (HOS). The HOS is a global, physician-led, multicenter observational database that collects information on the natural history of MPS II and the long-term safety and effectiveness of enzyme replacement therapy. As of January 2009, the HOS contained baseline data on joint range of motion in 124 males with MPS II. In total, 79% of patients had skeletal manifestations (median onset, 3.5 years) and 25% had abnormal gait (median onset, 5.4 years). Joint range of motion was restricted for all joints assessed (elbow, shoulder, hip, knee and ankle). Extension was the most severely affected movement: the exception to this was the shoulder. Surgery for orthopedic problems was rare. The presence of orthopedic manifestations was associated with the presence of central nervous system and pulmonary involvement, but not so clearly with cardiovascular involvement. Orthopedic interventions should be considered on an individual-patient basis. Although some orthopedic manifestations associated with MPS II may be managed routinely, a good knowledge of other concurrent organ system involvement is essential. A multidisciplinary approach is required. [ABSTRACT FROM AUTHOR]

Here, we show the effects of cryopreservation and hypothermic storage upon cell viability and enzyme release in alginate beads containing baby hamster kidney cells overexpressing alpha-L-iduronidase (IDUA), the enzyme deficient in mucopolysaccharidosis type I. In addition, we compared two different concentrations of alginate gel (1% and 1.5%) in respect to enzyme release from the beads and their shape and integrity. Our results indicate that in both alginate concentrations, the enzyme is released in lower amounts compared with nonencapsulated cells. Alginate 1% beads presented increased levels of IDUA release, although this group presented more deformities when compared with alginate 1.5% beads. Importantly, both encapsulated groups presented higher cell viability after long cryopreservation period and hypothermic storage. In addition, alginate 1.5% beads presented higher enzyme release after freezing protocols. Taken together, our findings suggest a benefic effect of alginate upon cell viability and functionality. These results may have important application for treatment of both genetic and nongenetic diseases using microencapsulation-based artificial organs. [ABSTRACT FROM AUTHOR]

Most lysosomal diseases (LD) are inherited as autosomal recessive traits, but two important conditions have X-linked inheritance: Fabry disease and Mucopolysaccharidosis II (MPS II). These two diseases show a very different pattern regarding expression on heterozygotes, which does not seem to be explained by the X-inactivation mechanism only. While MPS II heterozygotes are asymptomatic in most instances, in Fabry disease most of female carriers show some disease manifestation, which is sometimes severe. It is known that there is a major difference among X-linked diseases depending on the cell autonomy of the gene product involved and, therefore, on the occurrence of cross-correction. Since lysosomal enzymes are usually secreted and uptaken by neighbor cells, the different findings between MPS II and Fabry disease heterozygotes can also be due to different efficiency of cross-correction (higher in MPS II and lower in Fabry disease). In this paper, we review these two X-linked LD in order to discuss the mechanisms that could explain the different rates of penetrance and expressivity observed in the heterozygotes; this could be helpful to better understand the expression of X-linked traits. [ABSTRACT FROM AUTHOR]

Abstract: Recombinant human α-l-iduronidase (Aldurazyme®, laronidase) is approved as an enzyme replacement therapy to treat the lysosomal storage disorder, mucopolysaccharidosis type I (MPS I) at a dose of 0.58mg/kg by once-weekly intravenous infusion. To assess whether alternate dosing regimens might provide a better reduction in lysosomal storage, a 26-week, randomized, open-label, multinational dose-optimization trial was conducted. The pharmacodynamic effect and safety of the approved laronidase dose was compared to three alternative regimens (1.2mg/kg every 2 weeks; 1.2mg/kg every week; 1.8mg/kg every 2 weeks) among 33 MPS I patients. The four treatment regimens showed no significant differences in the reduction of urinary glycosaminoglycan excretion or liver volume. Laronidase had an acceptable safety profile in all dose regimen groups. Infusion-associated reactions were the most common drug-related adverse events across dose regimens (by patient incidence), and included pyrexia (21%), vomiting (15%), rash (15%), and urticaria (12%). Patients in the approved dose group had the lowest incidence of drug-related adverse events (38% vs. 63–75%) and infusion-associated reactions (25% vs. 25–63%). There was one death: a patient with acute bronchitis died of respiratory failure 6h after completing the first laronidase infusion. The approved 0.58mg/kg/week laronidase dose regimen provided near-maximal reductions in glycosaminoglycan storage and the best benefit-to-risk ratio. The 1.2mg/kg every 2 weeks regimen may be an acceptable alternative for patients with difficulty receiving weekly infusions, but the long-term effects of this regimen are unknown. [Copyright &y& Elsevier]

Enzyme replacement therapy (ERT) improves somatic manifestations in mucopolysaccharidoses (MPS). However, because intravenously administered enzymes cannot cross the blood–brain barrier (BBB), ERT is ineffective against the progressive neurodegeneration and resultant severe central nervous system (CNS) symptoms observed in patients with neuronopathic MPS. Attempts to surmount this problem have been made with intrathecal and intracerebroventricular ERT in order to achieve CNS effects, but the burdens on patients are inimical to long-term administrations. However, since pabinafusp alfa, a human iduronate-2-sulfatase fused with a BBB-crossing anti-transferrin receptor antibody, showed both central and peripheral efficacy in a mouse model, subsequent clinical trials in a total of 62 patients with MPS-II (Hunter syndrome) in Japan and Brazil substantiated this dual efficacy and provided an acceptable safety profile. To date, pabinafusp alfa is the only approved intravenous ERT that is effective against both the somatic and CNS symptoms of patients with MPS-II. This article summarizes the previously obtained preclinical and clinical evidence related to the use of this drug, presents latest data, and discusses the preclinical, translational, and clinical challenges of evaluating, ameliorating, and preventing neurodegeneration in patients with MPS-II. [ABSTRACT FROM AUTHOR]

Mucopolysaccharidosis VI (Maroteaux-Lamy syndrome) is a lysosomal storage disease that is characterized by systemic clinical manifestations and significant functional impairment. Diagnosis and management are often challenging because of the considerable variability in symptom presentation and rate of progression. The optimal standard of care should be based on evidence from randomized, controlled trials, meta-analyses, systematic reviews, and expert opinion. In support of this goal, comprehensive management guidelines have been drafted by an international group of experts in the management of patients with mucopolysaccharidosis VI. The guidelines provide a detailed outline of disease manifestations by body system, recommendations for regular assessments, and an overview of current treatment options. [ABSTRACT FROM AUTHOR]

Mucopolysaccharidosis IVA (MPS IVA) is a lysosomal storage disorder caused by the deficiency ofN-acetylgalactosamine-6-sulfate sulfatase (GALNS). Mutation screening of the GALNS was performed by genomic PCR and direct sequence analyses in 20 MPS IVA patients from Latin America. In this study, 12 different gene mutations including nine unreported ones were identified in 16 severe and four attenuated patients and accounted for 90.0% of the unrelated mutant alleles. The gene alterations were missense mutations except one insertion. Six recurrent mutations, p.A75G, p.G116S, p.G139S, p.N164T, p.R380S, and p.R386C, accounted for 5.0, 10.0, 5.0, 7.5, 5.0, and 32.5% of the unrelated mutant alleles, respectively. The p.R386C mutation was identified in all Latin American populations studied. Eleven mutations correlated with a severe form, while one mutation, p.R380S, was associated with an attenuated form. MPS IVA patients had an elevation of urine and plasma keratan sulfate (KS) concentrations compared with those of the age-matched control. KS concentrations in severe patients were higher than those in attenuated patients. These data provide evidence for extensive allelic heterogeneity and presence of a common mutation in Latin American patients. Accumulation of mutations with clinical description and KS concentration will lead us to predict clinical severity of the patient more precisely. [ABSTRACT FROM AUTHOR]

Background: In this study, the prevalence of different types of mucopolysaccharidoses (MPS) was estimated based on data from the exome aggregation consortium (ExAC) and the genome aggregation database (gnomAD). The population-based allele frequencies were used to identify potential disease-causing variants on each gene related to MPS I to IX (except MPS II).Methods: We evaluated the canonical transcripts and excluded homozygous, intronic, 3', and 5' UTR variants. Frameshift and in-frame insertions and deletions were evaluated using the SIFT Indel tool. Splice variants were evaluated using SpliceAI and Human Splice Finder 3.0 (HSF). Loss-of-function single nucleotide variants in coding regions were classified as potentially pathogenic, while synonymous variants outside the exon-intron boundaries were deemed non-pathogenic. Missense variants were evaluated by five in silico prediction tools, and only those predicted to be damaging by at least three different algorithms were considered disease-causing.Results: The combined frequencies of selected variants (ranged from 127 in GNS to 259 in IDUA) were used to calculate prevalence based on Hardy-Weinberg's equilibrium. The maximum estimated prevalence ranged from 0.46 per 100,000 for MPSIIID to 7.1 per 100,000 for MPS I. Overall, the estimated prevalence of all types of MPS was higher than what has been published in the literature. This difference may be due to misdiagnoses and/or underdiagnoses, especially of the attenuated forms of MPS. However, overestimation of the number of disease-causing variants by in silico predictors cannot be ruled out. Even so, the disease prevalences are similar to those reported in diagnosis-based prevalence studies.Conclusion: We report on an approach to estimate the prevalence of different types of MPS based on publicly available population-based genomic data, which may help health systems to be better prepared to deal with these conditions and provide support to initiatives on diagnosis and management of MPS. [ABSTRACT FROM AUTHOR]

Management of mucopolysaccharidosis (MPS) is complicated, therefore robust independent guidance is required. This program used a modified-Delphi methodology to develop evidence-based, expert-agreed recommendations for the management of patients with MPS IVA/VI. The program was led by an international, multidisciplinary Steering Committee (SC) of 29 MPS experts. Following a systematic literature review process, the SC developed 117 recommendation statements covering general principles, routine monitoring and assessments, interventions to treat the underlying disease and surgical interventions. The statements were ratified using a blinded modified-Delphi online survey in which they were rated using a Likert scale by international MPS physicians. Consensus was reached when ≥75% respondents agreed with a given statement and following two rounds of voting, all 117 statements reached consensus. During this process, the MPS community voted upon the use of enzyme replacement therapy (ERT) and hematopoietic stem cell therapy (HSCT) to address the underlying enzyme deficiency in patients with MPS IVA/VI. For each treatment the rationale, evidence base and deliberations for management (including safety and efficacy, monitoring response and adverse events) were considered at length. The expert consensus determined that the risk-profile benefit of HSCT in patients with MPS IVA/VI is less clear than in other types of MPS, and further research, including a comparative study to better understand the long-term efficacy and safety of HSCT is required. Therefore, initiation of long-term ERT is currently recommended as soon as possible after diagnosis for patients with MPS IVA/VI. Whilst HSCT is not currently recommended in patients with MPS IVA due to limited evidence, HSCT may be an option for patients with MPS VI with consideration of the associated safety risks, donor status and institution experience. Further research is required to address evidence gaps and to determine the long-term outcomes of ERT and HSCT in patients with MPS IVA/VI. [ABSTRACT FROM AUTHOR]