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ABSTRACTIntroductionLysosomal storage disorders (LSD) are a group of monogenic rare diseases caused by pathogenic variants in genes that encode proteins related to lysosomal function. These disorders are good candidates for gene therapy for different reasons: they are monogenic, most of lysosomal proteins are enzymes that can be secreted and cross-correct neighboring cells, and small quantities of these proteins are able to produce clinical benefits in many cases. Ex vivo gene therapy allows for autologous transplant of modified cells from different sources, including stem cells and hematopoietic precursors.Areas coveredHere, we summarize the main gene therapy and genome editing strategies that are currently being used as ex vivo gene therapy approaches for lysosomal disorders, highlighting important characteristics, such as vectors used, strategies, types of cells that are modified and main results in different disorders.Expert opinionClinical trials are already ongoing, and soon approved therapies for LSD based on ex vivo gene therapy approaches should reach the market.

BackgroundFabry disease is a rare, multisystemic disorder caused by GLAgene variants that lead to alpha galactosidase A deficiency, resulting in accumulation of glycosphingolipids and cellular dysfunction. Fabry-associated clinical events (FACEs) cause significant morbidity and mortality, yet the long-term effect of Fabry therapies on FACE incidence remains unclear.MethodsThis posthocanalysis evaluated incidence of FACEs (as a composite outcome and separately for renal, cardiac and cerebrovascular events) in 97 enzyme replacement therapy (ERT)-nai¨ve and ERT-experienced adults with Fabry disease and amenable GLAvariants who were treated with migalastat for up to 8.6 years (median: 5 years) in Phase III clinical trials of migalastat. Associations between baseline characteristics and incidence of FACEs were also evaluated.ResultsDuring long-term migalastat treatment, 17 patients (17.5%) experienced 22 FACEs and there were no deaths. The incidence rate of FACEs was 48.3 events per 1000 patient-years overall. Numerically higher incidence rates were observed in men versus women, patients aged >40 years versus younger patients, ERT-nai¨ve versus ERT-experienced patients and men with the classic phenotype versus men and women with all other phenotypes. There was no statistically significant difference in time to first FACE when analysed by patient sex, phenotype, prior treatment status or age. Lower baseline estimated glomerular filtration rate (eGFR) was associated with an increased risk of FACEs across patient populations.ConclusionsThe overall incidence of FACEs for patients during long-term treatment with migalastat compared favourably with historic reports involving ERT. Lower baseline eGFR was a significant predictor of FACEs.

This trial aimed to assess the efficacy and safety of olipudase alfa enzyme replacement therapy for non–central nervous system manifestations of acid sphingomyelinase deficiency (ASMD) in adults.

Due to their low frequency and some atypical presentations, inborn errors of metabolism are frequently misdiagnosed or underdiagnosed, which hinders the correct management of these patients. To illustrate that, here we present a patient that, at early school age, had learning disabilities compared to her classmates, especially for writing. She completed basic education in a regular school and was transferred to a secondary school for students with special needs. At 18 years of age, she presented a first psychiatric abrupt outbreak: she spent a month screaming and without sleeping. Behavioral problems then became apparent, especially hyperactivity, destructive and chaotic behavior, anxiety, and auto-aggressivity and hetero-aggressivity. A diagnosis of schizophreniform disorder was established. Clinical genetic evaluation revealed coarse face, macroglossia, coarse thick hair, and mild hepatomegaly, and the hypothesis of mucopolysaccharidosis-III was raised. Laboratory tests indicated high levels of urinary glycosaminoglycans and almost undetectable NAGLU activity, confirming the diagnosis. Sequencing of the NAGLUgene revealed the c.1318G>C (p.Gly440Arg) and c.1834A>G (p.Ser612Gly) mutations.

Mucopolysaccharidosis type II (MPS II) is an X‐linked inherited disease caused by pathogenic variants in the IDSgene, leading to deficiency of the lysosomal enzyme iduronate‐2‐sulfatase and consequent widespread storage of glycosaminoglycans, leading to several clinical consequences, with progressive manifestations which most times includes cognitive decline. MPS II has wide allelic and clinical heterogeneity and a complex genotype–phenotype correlation. We evaluated data from 501 Brazilian patients diagnosed with MPS II from 1982 to 2020. We genotyped 280 of these patients (55.9%), which were assigned to 206 different families. Point mutations were present in 70% of our patients, being missense variants the most frequent. We correlated the IDSpathogenic variants identified with the phenotype (neuronophatic or non‐neuronopathic). Except for two half‐brothers, there was no discordance in the genotype–phenotype correlation among family members, nor among MPS II patients from different families with the same single base‐pair substitution variant. Mothers were carriers in 82.0% of the cases. This comprehensive study of the molecular profile of the MPS II cases in Brazil sheds light on the genotype–phenotype correlation and helps the better understanding of the disease and the prediction of its clinical course, enabling the provision of a more refined genetic counseling to the affected families.

Latin American geneticists have been contributing to the scientific development of Human and Medical Genetics fields since the early 1950s. In the last decades, as Medical Genetics is moving toward a new era of innovative therapies for previously untreatable conditions, the participation of Latin America in clinical trials is also increasing. This review discusses the particularities regarding funding, regulatory, and ethical aspects of conducting clinical trials for genetic diseases in Latin America, with an especial focus on Brazil, the largest country with the highest number of studies. Although there are still several barriers to overcome, the recent development of orphan drug legislation and policies for rare diseases in many Latin American countries indicates a growing opportunity for the participation of the region in international efforts for the development of new therapies for genetic diseases.

To assess olipudase alfa enzyme replacement therapy for non–central nervous system manifestations of acid sphingomyelinase deficiency (ASMD) in children.

Mucopolysaccharidosis type I (MPS I) causes systemic accumulation of glycosaminoglycans due to a genetic deficiency of α-L-iduronidase (IDUA), which results in progressive systemic symptoms affecting multiple organs, including the central nervous system (CNS). Because the blood-brain barrier (BBB) prevents enzymes from reaching the brain, enzyme replacement therapy is effective only against the somatic symptoms. Hematopoietic stem cell transplantation can address the CNS symptoms, but the risk of complications limits its applicability. We have developed a novel genetically modified protein consisting of IDUA fused with humanized anti-human transferrin receptor antibody (lepunafusp alfa; JR-171), which has been shown in nonclinical studies to be distributed to major organs, including the brain, bringing about systemic reductions in heparan sulfate (HS) and dermatan sulfate concentrations. Subsequently, a first-in-human study was conducted to evaluate the safety, pharmacokinetics, and exploratory efficacy of JR-171 in 18 patients with MPS I. No notable safety issues were observed. Plasma drug concentration increased dose dependently and reached its maximum approximately 4 h after the end of drug administration. Decreased HS in the cerebrospinal fluid suggested successful delivery of JR-171 across the BBB, while suppressed urine and serum concentrations of the substrates indicated that its somatic efficacy was comparable to that of laronidase.

ObjectiveEarly 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 designData 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.ResultsData 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.ConclusionsTimes 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.

Mucopolysaccharidosis type I (MPS I) is caused by deficiency of alpha-L-iduronidase (IDUA), leading to multisystemic accumulation of glycosaminoglycans (GAG). Untreated MPS I patients may die in the first decades of life, mostly due to cardiovascular and respiratory complications. We previously reported that the treatment of newborn MPS I mice with intravenous administration of lipossomal CRISPR/Cas9 complexes carrying the murine Iduagene aiming at the ROSA26locus resulted in long-lasting IDUA activity and GAG reduction in various tissues. Following this, the present study reports the effects of gene editing in cardiovascular, respiratory, bone, and neurologic functions in MPS I mice. Bone morphology, specifically the width of zygomatic and femoral bones, showed partial improvement. Although heart valves were still thickened, cardiac mass and aortic elastin breaks were reduced, with normalization of aortic diameter. Pulmonary resistance was normalized, suggesting improvement in respiratory function. In contrast, behavioral abnormalities and neuroinflammation still persisted, suggesting deterioration of the neurological functions. The set of results shows that gene editing performed in newborn animals improved some manifestations of the MPS I disorder in bone, respiratory, and cardiovascular systems. However, further studies will be imperative to find better delivery strategies to reach “hard-to-treat” tissues to ensure better systemic and neurological effects.

IntroductionMucopolysaccharidoses (MPS) are a group of rare lysosomal storage diseases caused by different enzyme deficiencies that lead to accumulation of glycosaminoglycans (GAGs) in lysosomes and the extracellular matrix. This storage-induced inflammation is a key driver of cytopathology in MPS, and pharmacological immunomodulation can improve brain, cartilage and bone symptoms in rodents. As the approved enzyme replacement therapy cannot stop the progression of CNS involvement and several other symptoms, we develop a rational for personalized treatment to address the unmet clinical need in MPS patients.MethodsFirst, we conducted comprehensive literature reviews on MPS type specific inflammatory immune response and on the safety and efficacy of Adalimumab, Infliximab, Abatacept, Alemtuzumab, Anakinra. Second, by expert consensus top candidates for innovative personalized drug repurposing in MPS patients were identified and ranked.ResultsThe key process is the upregulation of toll-like receptor-4 (TLR4) pathway induced by the accumulation of heparan sulfate (HS) in MPS type I, II and III. This and other relevant mech-anisms indicate TNF-alpha and IL-1 as most promising targets. Systematic analysis of the clinical pharmacology of all relevant candidates and several expert focus group meetings identified Anakinra, Adalimumab, Cladribine and Abatacept as top candidate’s dependent on the individual clinical situation.ConclusionsThese results provide the rational for individual treatment trials (ITTs) with the aim to evaluate immunomodulatory molecules, repurposed in MPS. Furthermore, they will – together with the results of the ITTs – be utilized for the development of a decision tool for the personalized treatment of unmet clinical needs in these patients.

Outcomes in patients with Fabry disease receiving migalastat during the phase 3 FACETS trial (NCT00925301) were evaluated by phenotype.

Lysosomal disorders have been an area of interest since intravenous enzyme replacement therapy was successfully introduced for the treatment of Gaucher's disease in the early 1990s. This treatment approach has also been developed for several other lysosomal disorders, including Fabry's disease, Pompe's disease, lysosomal acid lipase deficiency, and five types of mucopolysaccharidosis. Despite the benefits of enzyme replacement therapy, it has limitations—most importantly, its ineffectiveness in treating the neurological components of lysosomal disorders, as only a small proportion of recombinant enzymes can cross the blood–brain barrier. Development of strategies to improve drug delivery to the CNS is now the primary focus in lysosomal disorder research. This Review discusses the neurological manifestations and emerging therapies for the CNS component of these diseases. The therapies in development (which are now in phase 1 or phase 2 clinical trials) might be for specific lysosomal disorders (enzyme replacement therapy via intrathecal or intracerebroventricular routes or with fusion proteins, or gene therapy) or applicable to more than one lysosomal disorder (haemopoietic stem cell transplantation, pharmacological chaperones, substrate reduction therapy, or stop codon readthrough). The combination of early diagnosis with effective therapies should change the outlook for patients with lysosomal disorders with neurological involvement in the next 5–10 years.

ABSTRACTIntroduction: The mucopolysaccharidoses are lysosomal diseases characterized by deficient activity of one of the enzymes that degrades glycosaminoglycans. Treatment options are limited; therefore, new treatments are under investigation.Areas covered: We review the medicinal products for the treatment of mucopolysaccharidoses that are currently being investigated in phase I and phase II clinical trials.Expert opinion: The number of alternatives to treat MPS diseases increased dramatically in an attempt to provide therapy options for orphan MPS diseases and to address the unmet needs of the MPS that already have a treatment available. Intravenous enzyme replacement therapy (ERT) with fusion proteins, intrathecal/intracerebroventricular (ICV) ERT and gene therapy are the most promising strategies addressing the CNS manifestations. Stop-codon read-through, although proposed only for patients with nonsense mutations, might be useful in all MPS types. Substrate reduction therapy could also play a role in any MPS type, as anti-inflammatory drugs are also being tested. This new generation of therapies is now in clinical development and should bring new hope to MPS patients. As cost and logistics remain major challenges, especially for low- and middle-income countries, the possibility of having a one-time treatment such as gene therapy is anxiously awaited by affected families and healthcare systems.

Disclaimer:This diagnostic guideline is intended as an educational resource and represents the opinions of the authors, and is not representative of recommendations or policy of the American College of Medical Genetics and Genomics (ACMG). The information should be considered a consensus based on expert opinion, as more comprehensive levels of evidence were not available in the literature in all cases.Background:Acid sphingomyelinase deficiency (ASMD) is a rare, progressive, and often fatal lysosomal storage disease. The underlying metabolic defect is deficiency of the enzyme acid sphingomyelinase that results in progressive accumulation of sphingomyelin in target tissues. ASMD manifests as a spectrum of severity ranging from rapidly progressive severe neurovisceral disease that is uniformly fatal to more slowly progressive chronic neurovisceral and chronic visceral forms. Disease management is aimed at symptom control and regular assessments for multisystem involvement.Purpose and methods:An international panel of experts in the clinical and laboratory evaluation, diagnosis, treatment/management, and genetic aspects of ASMD convened to review the evidence base and share personal experience in order to develop a guideline for diagnosis of the various ASMD phenotypes.Conclusions:Although care of ASMD patients is typically provided by metabolic disease specialists, the guideline is directed at a wide range of providers because it is important for primary care providers (e.g., pediatricians and internists) and specialists (e.g., pulmonologists, hepatologists, and hematologists) to be able to identify ASMD.Genet Med advance online publication 13 April 2017

Purpose:Fabry disease is an X-linked lysosomal storage disorder caused by mutations in the α-galactosidase A gene. Migalastat, a pharmacological chaperone, binds to specific mutant forms of α-galactosidase A to restore lysosomal activity.Methods:A pharmacogenetic assay was used to identify the α-galactosidase A mutant forms amenable to migalastat. Six hundred Fabry disease–causing mutations were expressed in HEK-293 (HEK) cells; increases in α-galactosidase A activity were measured by a good laboratory practice (GLP)-validated assay (GLP HEK/Migalastat Amenability Assay). The predictive value of the assay was assessed based on pharmacodynamic responses to migalastat in phase II and III clinical studies.Results:Comparison of the GLP HEK assay results in in vivo white blood cell α-galactosidase A responses to migalastat in male patients showed high sensitivity, specificity, and positive and negative predictive values (≥0.875). GLP HEK assay results were also predictive of decreases in kidney globotriaosylceramide in males and plasma globotriaosylsphingosine in males and females. The clinical study subset of amenable mutations (n = 51) was representative of all 268 amenable mutations identified by the GLP HEK assay.Conclusion:The GLP HEK assay is a clinically validated method of identifying male and female Fabry patients for treatment with migalastat.Genet Med 19 4, 430–438.

Fabry disease is an X-linked lysosomal storage disorder caused by mutations in the α-galactosidase A gene. Migalastat, a pharmacological chaperone, binds to specific mutant forms of α-galactosidase A to restore lysosomal activity.

What is mucopolysaccharidosis type I?Mucopolysaccharidosis type I (also called MPS I) is a rare genetic condition that affects most parts of the body. MPS I develops when both parents pass a nonworking copy of the IDUAgene onto their child. This gene carries the information needed for cells to make the alpha-L-iduronidase enzyme, which breaks down complex sugar molecules called glycosaminoglycans (shortened to GAGs) inside cells. Individuals with MPS I do not produce a working (fully functional) version of the enzyme or might not produce any of it at all. Therefore, GAGs build up in their cells and bodies, which can lead to organ damage. Symptoms of MPS I include an enlarged liver and spleen, abnormal bone development, and specific facial characteristics. It is important to diagnose and treat MPS I as early in life as possible to prevent irreversible organ damage. There are two ways that individuals with MPS I can be treated, depending on how severe their disease is. Individuals with less severe, or ‘attenuated’, MPS I (Hurler-Scheie or Scheie syndrome) typically receive enzyme replacement therapy (shortened to ERT). This replaces the non-functional or missing enzyme. Those with severe MPS I (Hurler syndrome) typically undergo hematopoietic stem cell transplantation (also called HSCT), and ERT may also be used until the transplanted cells start making the enzyme. In HSCT, individuals receive stem cells from healthy donors so that their body can make the life-sustaining enzyme. This study looked at the age when individuals were diagnosed with attenuated or severe MPS I between 2003 and 2017, and the time taken for them to start treatment with ERT or HSCT following their diagnosis, using data from the MPS I Registry.What were the results?The age when individuals received a diagnosis of attenuated or severe MPS I did not change during the study period. The time taken from being diagnosed with attenuated MPS I to starting ERT decreased over time. The time taken from being diagnosed with severe MPS I to receiving HSCT was very short for the entire study period.What do the results of the study mean?These findings suggest that improvements in MPS I awareness and diagnosis are still needed.Clinical Trial Registration: NCT00144794(ClinicalTrials.gov)

What is MPS I & what is this study about?Mucopolysaccharidosis type I (MPS I) is a rare genetic condition, resulting from disease-causing changes in the IDUA gene called pathogenic variants. There are two different types of variants: Null variants – cells cannot make the alpha-L-iduronidase enzymeMissense variants – cells make a partly functional or severely reduced amount of the fully functional enzymeThe alpha-L-iduronidase enzyme breaks down large sugar molecules called glycosaminoglycans (GAGs). In people with MPS I, the enzyme is unable to break down GAGs and they build up in cells. Based on the severity of the condition, doctors categorise MPS I into two types, called phenotypes:Attenuated MPS ISevere MPS ITreatment options differ depending on MPS I phenotype. There are currently no tests that accurately determine MPS I phenotype. Using information from the MPS I Registry, researchers wanted to find out whether knowing the specific combination of the 2 disease-causing gene variants (genotype) can help predict whether a person has an attenuated or severe phenotype.What were the results?In people with attenuated MPS I: 19 in 20 had genotypes where at least one of the gene copies was a missense variant. The cell makes a partly functional or a severely reduced amount of the fully functional enzyme, and is unable to completely break down GAGNo-one had 2 null variants2 in 5 had unique genotypes (their genotype was only seen in one person)In people with severe MPS I:2 in 3 had genotypes where both copies of the gene contained null variants. The cell is not able to make any enzyme1 in 5 had unique genotypesWhat do the results mean?This study showed that genotype can predict phenotype in some people with MPS I. For example, if a person has inherited two copies of the genes containing null variants, they will have severe MPS I. However, due to the large number of unique gene variants found in this study, doctors cannot predict the severity of MPS I from just the genotype for some people.

IntroductionMucopolysaccharidoses (MPS), comprise a group of rare chronically debilitating metabolic diseases and associated with reduced life expectancy and a substantial unmet clinical need. Current research directs towards a number of new treatment targets and strategies. Individual treatment trials (ITT) could make these options rapidly available to patients. Based on scientific publication, this is hardly used. We assess the utilization of and relevant barriers to ITT in MPS as well as potential solutions.MethodsPhase 1 was done with 5 international top experts. After this interim analysis, the survey will be rolled out to a broader group of experts.ResultsFive MPS experts from Austria, Brazil, Germany and Italy have been enrolled. In total these clinicians manage about 350 MPS patients. Only three experts ever ran 1–3 numbers of ITT in MPS patients, solely MPS type II (n=2) and VI (n=1), summing up to a total of five ITTs, which is about 1.4% of their patients. The treatments used in ITTs comprise Montelukast, THC, Curcuma and a viral vector with transgene. As barriers for a wider use of ITTs, the im-practicability for implementation (n=1) and the insufficient training in ITT (n=1) have been indicated. All experts consider it highly likely that a decision analysis tool increases the use of ITT in MPS.ConclusionsITT are used in about 1% of MPS patients. This seems extremely low, considering the commonness of off label use in children with severe conditions, the high unmet medical need in MPS and the number of research results, which indicate various promising repurposing strategies. This interim analysis already demonstrates several relevant barriers and high potential of the planned decision framework tool to overcome this.

Purpose:CDKN2A is the main high-risk melanoma-susceptibility gene, but it has been poorly assessed in Latin America. We sought to analyze CDKN2A and MC1R in patients from Latin America with familial and sporadic multiple primary melanoma (SMP) and compare the data with those for patients from Spain to establish bases for melanoma genetic counseling in Latin America.Methods:CDKN2A and MC1R were sequenced in 186 Latin American patients from Argentina, Brazil, Chile, Mexico, and Uruguay, and in 904 Spanish patients. Clinical and phenotypic data were obtained.Results:Overall, 24 and 14% of melanoma-prone families in Latin America and Spain, respectively, had mutations in CDKN2A. Latin American families had CDKN2A mutations more frequently (P = 0.014) than Spanish ones. Of patients with SMP, 10% of those from Latin America and 8.5% of those from Spain had mutations in CDKN2A (P = 0.623). The most recurrent CDKN2A mutations were c.-34G>T and p.G101W. Latin American patients had fairer hair (P = 0.016) and skin (P < 0.001) and a higher prevalence of MC1R variants (P = 0.003) compared with Spanish patients.Conclusion:The inclusion criteria for genetic counseling of melanoma in Latin America may be the same criteria used in Spain, as suggested in areas with low to medium incidence, SMP with at least two melanomas, or families with at least two cases among first- or second-degree relatives.Genet Med 18 7, 727–736.

CDKN2Ais the main high-risk melanoma-susceptibility gene, but it has been poorly assessed in Latin America. We sought to analyze CDKN2Aand MC1Rin patients from Latin America with familial and sporadic multiple primary melanoma (SMP) and compare the data with those for patients from Spain to establish bases for melanoma genetic counseling in Latin America.

ABSTRACTIntroduction: Despite being reported for the first time almost one century ago, only in the last few decades effective have treatments become available for the mucopolysaccharidoses (MPSs), a group of 11 inherited metabolic diseases that affect lysosomal function. These diseases are progressive, usually severe, and, in a significant number of cases, involve cognitive impairment.Areas covered: This review will not cover established treatments such as bone marrow/hematopoietic stem cell transplantation and classic intravenous enzyme replacement therapy (ERT), whose long-term outcomes have already been published (MPS I, MPS II, and MPS VI), but it instead focuses on emerging therapies for MPSs. That includes intravenous ERT for MPS IVA and VII, intrathecal ERT, ERT with fusion proteins, substrate reduction therapy, gene therapy, and other novel approaches.Expert opinion: The available treatments have resulted in improvements for several disease manifestations, but they still do not represent a cure for these diseases; thus, it is important to develop alternative methods to approach the unmet needs (i.e. bone disease, heart valve disease, corneal opacity, and central nervous system (CNS) involvement). The work in progress with novel approaches makes us confident that in 2017, when MPS will commemorate 100 years of its first report, we will be much closer to an effective cure for these challenging conditions.

Los Errores Innatos del Metabolismo (EIM) son un grupo de condiciones caracterizadas por el acúmulo de sustancias tóxicas producido habitualmente por un defecto enzimático. Su relevancia dentro del grupo de las Enfermedades Raras, es que son consideradas hoy un conjunto de patologías tratables, ya que han sido particularmente beneficiadas por leyes de drogas huérfanas, permitiendo el acceso a terapias seguras y eficaces en tratar sus síntomas y la causa que las produce.

To identify chromosomal imbalances by whole-genome microarray-based comparative genomic hybridization (array-CGH) in DNA samples of neonates with congenital anomalies of unknown cause from a birth defects monitoring program at a public maternity hospital.

To identify chromosomal imbalances by whole‐genome microarray‐based comparative genomic hybridization (array‐CGH) in DNA samples of neonates with congenital anomalies of unknown cause from a birth defects monitoring program at a public maternity hospital.

Purpose:In this study, we aimed to describe the natural history of mucopolysaccharidosis I.Methods:Data from 1,046 patients who enrolled in the MPS I Registry as of August 2013 were available for descriptive analysis. Only data from untreated patients and data prior to treatment for patients who received treatment were considered. Age at symptom onset, diagnosis, and treatment initiation were examined by geographic region and phenotype (from most to least severe: Hurler, Hurler–Scheie, and Scheie). For each symptom, frequency and age at onset were examined.Results:Natural history data were available for 987 patients. Most patients were from Europe (45.5%), followed by North America (34.8%), Latin America (17.3%), and Asia Pacific (2.4%). Phenotype distribution was 60.9% for Hurler, 23.0% for Hurler–Scheie, and 12.9% for Scheie (3.2% undetermined) syndromes. Median age at symptom onset for Hurler, Hurler–Scheie, and Scheie syndromes was 6 months, 1.5 years, and 5.3 years, respectively; median age at treatment initiation was 1.5 years, 8.0 years, and 16.9 years, respectively. Coarse facial features and corneal clouding were among the most common symptoms in all three phenotypes.Conclusion:A delay between symptom onset and treatment exists, especially in patients with attenuated mucopolysaccharidosis I. A better understanding of disease manifestations may help facilitate prompt diagnosis and treatment and improve patient outcomes.Genet Med 16 10, 759–765.

In this study, we aimed to describe the natural history of mucopolysaccharidosis I.

The primary objective of this study was to determine the safety of idursulfase in Hunter syndrome patients aged 5 years or younger.

Purpose:The primary objective of this study was to determine the safety of idursulfase in Hunter syndrome patients aged 5 years or younger.Methods:Idursulfase (0.5?mg/kg) was administered intravenously on a weekly basis (52 infusions per patient) in an open-label study. Safety monitoring included adverse events, anti-idursulfase antibodies, vital signs, physical examination, 12-lead electrocardiogram, concomitant medications or procedures, and laboratory testing (clinical chemistry, hematology, and urinalysis). The following exploratory efficacy outcomes were assessed at baseline and at weeks 18 or 36 or 53: urinary glycosaminoglycan levels, liver or spleen size, developmental milestones, and growth indices. Pharmacokinetic parameters were assessed at week 27.Results:Twenty-eight boys aged 1.4–7.5 years were enrolled (one discontinued for noncompliance) in the study. All the patients reported adverse events (16 patients (57%) reported possibly or probably treatment-related adverse events). The only severe adverse event was sleep apnea (two patients); others were mild or moderate. Sixteen patients had infusion-related adverse events, a similar proportion as previously reported. Thirteen patients (46%) experienced at least one serious adverse event: pyrexia and bronchopneumonia were the most common (three patients each). No clinically important drug-related changes in laboratory parameters or vital signs or electrocardiograms were reported. Nineteen patients (68%) developed anti-idursulfase immunoglobulin G antibodies. Growth rates remained within normal age-related ranges. Developmental quotients were lower than normal but remained stable. By week 18, organ size and urinary glycosaminoglycan levels decreased as compared with baseline and remained stable throughout the study.Conclusion:Idursulfase safety, tolerability, and efficacy were similar to that previously reported in males =5 years.Genet Med 16 6, 435–441.

Introduction:Mucopolysaccharidosis (MPS) disorders are genetic diseases caused by deficiencies in the lysosomal enzymes responsible for the degradation of glycosaminoglycans. Current treatments are not able to correct all disease symptoms and are not available for all MPS types, which makes gene therapy especially relevant. Multiple gene therapy approaches have been tested for different types of MPS, and our aim in this study is to critically analyze each of them.Areas covered:In this review, we have included the major studies that describe the use of adeno-associated retroviral and lentiviral vectors, as well as relevant non-viral approaches for MPS disorders.Expert opinion:Some protocols such as the use of adeno-associated vectors and lentiviral vectors are approaching the clinic for these disorders and, along with combined approaches, seem to be the future of gene therapy for MPS.

Objective:The aim of the present study was to assess anthropometric measurements, nutritional status, dietary intake, and body fat percentage of pediatric patients with osteogenesis imperfecta (OI).Method:A cross-sectional study evaluated 63 OI patients from 0 to 19 years of age. We analyzed anthropometric measurements, mobility, bisphosphonate treatment, body fat percentage (by dual-energy x-ray absorptiometry [DEXA] and sum of skinfold thickness), nutritional status, and dietary intake (using World Health Organization [WHO] and dietary reference intake recommendations for macronutrients and calcium intake, respectively). Participants’ energy requirements were calculated using both kilocalorie per centimeter measurements and WHO methods.Results:Patients with different types of OI had different anthropometric measurements (p< 0.05), where OI type III had severely limited stature and poor mobility. Nutritional status was correlated with measurements of arm circumference and body fat. We also found a strong correlation between the 2 methods used to calculate percentage of body fat (r= 0.803). OI type III had a higher percentage of energy intake. We observed that 75% of subjects had a calcium intake below 95% of recommended daily value and there was an inverse correlation between age and calcium intake.Conclusions:This study showed that stature was compromised mainly in OI type III. Skinfold thickness and arm circumference correlated to nutritional status and also to body fat calculated by DEXA. Daily calcium intake was below the recommended levels in pediatric patients with OI. These findings are important for the management of OI subjects.

Background:Jaundice is a physiological phenomenon; however, severe hyperbilirubinemia occurs in only 5 to 6% of the healthy newborn population. It has been suggested that genetic variation could enhance the risk of hyperbilirubinemia when coexpressed with other icterogenic conditions.Methods:The study included newborns with a gestational age of greater than 35?wk and weights greater than 2,000?g with indications for phototherapy. The polymorphisms from UGT1A1 (rs8175347), SLCO1B1 (rs4149056 and rs2306283), and SLCO1B3 (rs17680137 and rs2117032) were analyzed by capillary electrophoresis and hydrolysis probes.Results:A total of 167 hyperbilirubinemic infants and 247 control subjects were enrolled. The gender, ABO incompatibility, birth weight, and gestational age differed between the groups, but the allelic and genotypic frequency of the polymorphisms from SLCO1B genes did not. In logistic regression, the ABO incompatibility, gestational age, and polymorphic T allele of rs2117032 remained in the model. The presence of this polymorphism seemed to provide protection from hyperbilirubinemia. The individuals who were homozygous for the G allele of rs2306283 and who were glucose 6-phosphate-dehydrogenase deficient were more frequent among the cases.Conclusion:Although genetic variation accounts for a good part of this condition, the association between different polymorphisms and environmental factors has yet to be explained.

The aim of this study was to investigate the effect of aging and timing of left ventricular ischemic injury on the availability and functionality of stem cells. We studied young and aged male inbred Lewis rats that were used as donors of bone marrow mononuclear cells (BM-MNCs), divided in four experimental groups: controls, sham operated, 48 h post-myocardial infarction (MI), and 28 days post-MI. In vitro studies included flow cytometry analysis, hematopoietic colony-forming capacity, and invasion assays of migration capacity. BM-MNCs from these groups were transplanted in female rats after MI induction. Late engraftment was evaluated by real-time PCR of the SRY chromosome. Percentage of CD34+/CD45+lowcells was similar among different experimental groups in young rats, but was significantly higher in aged animals (p< 0.001), particularly 28 days post-MI. KDR+/CD34+cells were increased 48 h after MI and decreased 28 days post-MI in young animals, while they were profoundly reduced in the aged group (p< 0.001). Triple staining for CD44+/CD29+/CD71+cells was similar in different groups of aged rats, but we observed an intense increase 48 h post-MI in young animals. Colony-forming units and cytokine-induced migration were significantly attenuated 28 days after the MI. Late engraftment in infarcted transplanted female hearts was present, but considerably heterogeneous. Finally, recovery of left ventricular systolic function in transplanted female recipients was significantly influenced by donors' BM-MNCs groups (p< 0.01). We have demonstrated that aging and timing of myocardial injury are factors that may act synergistically in determining stem cell availability and function. Such interaction should be considered when planning new cell therapy strategies for acute and chronic ischemic heart disease in the clinical arena.

Purpose: This study evaluated the safety and effectiveness of long-term enzyme replacement therapy with idursulfase (recombinant human iduronate-2-sulfatase) in patients with Hunter syndrome.Methods: All 94 patients who completed a 53-week double-blinded study of idursulfase enrolled in this open-labeled extension study and received intravenous idursulfase at a dose of 0.5 mg/kg weekly for 2 years, and clinical outcomes and safety were assessed.Results: No change in percent predicted forced vital capacity was seen, but absolute forced vital capacity demonstrated sustained improvement and was increased 25.1% at the end of the study. Statistically significant increases in 6-minute walking test distance were observed at most time points. Mean liver and spleen volumes remained reduced throughout the 2-year extension study. Mean joint range of motion improved for the shoulder and remained stable in other joints. Both the parent- and child-assessed Child Health Assessment Questionnaire Disability Index Score demonstrated significant improvement. Infusion-related adverse events occurred in 53% of patients and peaked at Month 3 of treatment and declined thereafter. Neutralizing IgG antibodies were detected in 23% of patients and seemed to attenuate the improvement in pulmonary function.Conclusions: Weekly infusions of idursulfase result in sustained clinical improvement during 3 years of treatment.

Purpose: To use the Hunter Outcome Survey, an international database, to assess the safety and effectiveness of enzyme replacement therapy with idursulfase in patients with Hunter syndrome who started treatment before 6 years of age.Methods: The study population included all patients enrolled in the Hunter Outcome Survey who started idursulfase infusions (0.5 mg/kg every other week) before 6 years of age and who had at least one follow-up examination recorded.Results: The study population included 124 patients, younger than 6 years, who had a mean age at start of idursulfase of 3.6 ± 1.6 years (mean ± SD). The mean duration of treatment was 22.9 ± 14.6 months. A total of 69 infusion-related reactions occurred in 33 (26.6%) patients, including three serious infusion-related reactions occurring in a single patient. After at least 6 months of idursulfase, urine glycosaminoglycan levels decreased from 592 ± 188 to 218 ± 115 µg/mg creatinine (P < 0.0001, n = 34). Liver size, estimated by palpation, was also significantly decreased (P = 0.005, n = 23). Similar safety and effectiveness results were seen in patients who were aged 6 years or older when initiating idursulfase.Conclusion: No new safety concerns were identified in patients younger than 6 years, and clinical benefit was suggested by the reduction in liver size.