Search

Fabiano de Oliveira Poswar,1– 4 Johanna Henriques Nehm,1 Francyne Kubaski,5 Edina Poletto,6 Roberto Giugliani1– 4,7– 9 1Clinical Research Group in Medical Genetics, Clinical Research Center, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil; 2Medical Genetics Service, Hospital de Clinicas de Porto Alegre, Porto Alegre, RS, Brazil; 3Postgraduate Program in Genetics and Molecular Biology, UFRGS, Porto Alegre, RS, Brazil; 4DR Brasil Research Group, HCPA, Porto Alegre, RS, Brazil; 5Greenwood Genetic Center, Biochemical Genetics Laboratory, Greenwood, SC, USA; 6Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA; 7Department of Genetics, UFRGS, Porto Alegre, RS, Brazil; 8DASA Genômica, São Paulo, SP, Brazil; 9Casa dos Raros, Porto Alegre, RS, BrazilCorrespondence: Roberto Giugliani, Medical Genetics Service- HCPA / Dep Genet UFRGS, 2350 Ramiro Barcelos, Porto Alegre, RS, 90035-903, Brazil, Tel +55 51 3359 6338, Email rgiugliani@hcpa.edu.brAbstract: 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.Keywords: lysosomal disorders, mucopolysaccharidosis type VII, Sly syndrome, enzyme replacement therapy, hematopoietic stem cell transplantation, gene therapy

Uma Ramaswami,1 Michael Beck,2 Derralynn Hughes,1 Christoph Kampmann,2 Jaco Botha,3 Guillem Pintos-Morell,4 Michael L West,5 Dau-Ming Niu,6 Kathy Nicholls,7,8 Roberto Giugliani9 On behalf of the FOS Study Group 1Royal Free London NHS Foundation Trust, Lysosomal Disorders Unit, Institute of Immunity and Transplantation, London, UK; 2Centre for Paediatric and Adolescent Medicine, University Medical Centre, University of Mainz, Mainz, Germany; 3Department of Biostatistics and Programming, Takeda, Zug, Switzerland; 4Centre for Rare Diseases, University Hospital Vall d’Hebron, Barcelona, CIBERER-GCV08_IGTP Research Institute and Teaching Unit Germans Trias i Pujol, Universitat Autònoma de Barcelona, Badalona, Spain; 5Department of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada; 6Department of Paediatrics, Taipei Veterans General Hospital, Taipei, Taiwan; 7Department of Nephrology, Royal Melbourne Hospital, University of Melbourne, Parkville, VIC, Australia; 8Department of Medicine, Royal Melbourne Hospital, University of Melbourne, Parkville, VIC, Australia; 9Medical Genetics Service HCPA, Department of Genetics, UFRGS, and INAGEMP, Porto Alegre, BrazilCorrespondence: Uma RamaswamiLysosomal Disorders Unit, Institute of Immunity and Transplantation, 2nd Floor, Royal Free Hospital, Pond Street, London NW3 2QG, UKTel +44 207 794 0500 Ext 22492Fax +44 207 317 7665Email uma.ramaswami@nhs.netPurpose: Following the publication of 5-year agalsidase alfa enzyme replacement therapy (ERT) outcomes data from the Fabry Outcome Survey (FOS), 10-year data were analyzed.Patients and methods: FOS (ClinicalTrials.gov identifier: NCT03289065) data (April 2001 to August 2018) were retrospectively analyzed. Estimated glomerular filtration rate (eGFR) and left ventricular mass indexed to height (LVMI) were analyzed after treatment start (baseline) for patients with ≥3 measurements, including baseline and year 10.Results: Median (range) age (years) of the evaluable treated renal cohort at treatment start was 48.8 (17.9–67.3) for females (n=62), 34.4 (18.0–66.8) for males (n=90). With eGFR ≥60 mL/min/1.73 m2 at baseline, mean (95% CI) rate of eGFR change (eGFR/year) over 10 years was relatively stable in females (n=52; −0.55 [−1.12, +0.01]) and slightly declined in males (n=79; −1.99 [−2.45, −1.54]). With impaired kidney function (eGFR 48 g/m2.7 in females, >50 g/m2.7 in males) at baseline, mean (95% CI) LVMI/year slightly increased over 10 years in females (n=18; +1.51 [+0.91, +2.12]) and males (n=14; +0.87 (+0.19, +1.55). Without LVH at baseline, mean (95% CI) LVMI/year was stable in females (n=16; +0.52 [−0.13, +1.17]) and males (n=21; +0.57 [+0.02, +1.13]) over 10 years.Conclusion: Agalsidase alfa-treated patients with 10-year FOS data and preserved kidney function and/or normal LVMI at baseline remained largely stable; those with decreased kidney function or LVH at baseline experienced modest declines in renal function and/or increases in LVMI.Keywords: agalsidase alfa, enzyme replacement therapy, Fabry disease, cardio-renal outcomes

Filippo Vairo,1–3 Andressa Federhen,1,3,4 Guilherme Baldo,1,2,5–7 Mariluce Riegel,1,6 Maira Burin,1 Sandra Leistner-Segal,1,8 Roberto Giugliani1,5,6,81Medical Genetics Service, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil; 2Department of Genetics, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; 3Clinical Research Group on Medical Genetics, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil; 4Post-Graduate Program in Child and Adolescent Health, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; 5Gene Therapy Center, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil; 6Post-Graduate Program in Genetics and Molecular Biology, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; 7Department of Physiology, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; 8Post-Graduate Program in Medical Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, BrazilAbstract: 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.Keywords: mucopolysaccharidosis VI, Maroteaux–Lamy syndrome, dermatan sulfate, arylsulfatase b, enzyme replacement therapy, lysosomal storage diseases

Shunji Tomatsu,1,2 Kazuki Sawamoto,1 Carlos J Alméciga-Díaz,3 Tsutomu Shimada,1 Michael B Bober,1 Yasutsugu Chinen,4 Hiromasa Yabe,5 Adriana M Montaño,6 Roberto Giugliani,7 Francyne Kubaski,1,8 Eriko Yasuda,1 Alexander Rodríguez-López,3 Angela J Espejo-Mojica,3 Oscar F Sánchez,9 Robert W Mason,1 Luis A Barrera,3 William G Mackenzie,1 Tadao Orii2 1Nemours/Alfred I duPont Hospital for Children, Wilmington, DE, USA; 2Department of Pediatrics, Gifu University, Gifu, Japan; 3Institute for the Study of Inborn Errors of Metabolism, School of Sciences, Pontificia Universidad Javeriana, Bogotá, Colombia; 4Department of Pediatrics, Faculty of Medicine, University of the Ryukyus, Okinawa, 5Department of Cell Transplantation and Regenerative Medicine, Tokai University School of Medicine, Isehara, Japan; 6Department of Pediatrics, Saint Louis University, St Louis, MO, USA; 7Medical Genetics Service/HCPA and Department of Genetics/UFRGS, Porto Alegre, Brazil; 8Department of Biological Sciences, University of Delaware, Newark, DE, 9School of Chemical Engineering, Purdue University, West Lafayette, IN, USA Abstract: Patients with mucopolysaccharidosis IVA (MPS IVA) can present with systemic skeletal dysplasia, leading to a need for multiple orthopedic surgical procedures, and often become wheelchair bound in their teenage years. Studies on patients with MPS IVA treated by enzyme replacement therapy (ERT) showed a sharp reduction on urinary keratan sulfate, but only modest improvement based on a 6-minute walk test and no significant improvement on a 3-minute climb-up test and lung function test compared with the placebo group, at least in the short-term. Surgical remnants from ERT-treated patients did not show reduction of storage materials in chondrocytes. The impact of ERT on bone lesions in patients with MPS IVA remains limited. ERT seems to be enhanced in a mouse model of MPS IVA by a novel form of the enzyme tagged with a bone-targeting moiety. The tagged enzyme remained in the circulation much longer than untagged native enzyme and was delivered to and retained in bone. Three-month-old MPS IVA mice treated with 23 weekly infusions of tagged enzyme showed marked clearance of the storage materials in bone, bone marrow, and heart valves. When treatment was initiated at birth, reduction of storage materials in tissues was even greater. These findings indicate that specific targeting of the enzyme to bone at an early stage may improve efficacy of ERT for MPS IVA. Recombinant N-acetylgalactosamine-6-sulfate sulfatase (GALNS) in Escherichia coli BL21 (DE3) (erGALNS) and in the methylotrophic yeast Pichia pastoris (prGALNS) has been produced as an alternative to the conventional production in Chinese hamster ovary cells. Recombinant GALNS produced in microorganisms may help to reduce the high cost of ERT and the introduction of modifications to enhance targeting. Although only a limited number of patients with MPS IVA have been treated with hematopoietic stem cell transplantation (HSCT), beneficial effects have been reported. A wheelchair-bound patient with a severe form of MPS IVA was treated with HSCT at 15 years of age and followed up for 10 years. Radiographs showed that the figures of major and minor trochanter appeared. Loud snoring and apnea disappeared. In all, 1 year after bone marrow transplantation, bone mineral density at L2–L4 was increased from 0.372 g/cm2 to 0.548 g/cm2 and was maintained at a level of 0.48±0.054 for the following 9 years. Pulmonary vital capacity increased approximately 20% from a baseline of 1.08 L to around 1.31 L over the first 2 years and was maintained thereafter. Activity of daily living was improved similar to the normal control group. After bilateral osteotomies, a patient can walk over 400 m using hip–knee–ankle–foot orthoses. This long-term observation of a patient shows that this treatment can produce clinical improvements although bone deformity remained unchanged. In conclusion, ERT is a therapeutic option for MPS IVA patients, and there are some indications that HSCT may be an alternative to treat this disease. However, as neither seems to be a curative therapy, at least for the skeletal dysplasia in MPS IVA patients, new approaches are investigated to enhance efficacy and reduce costs to benefit MPS IVA patients. Keywords: mucopolysaccharidosis IVA, ERT, HSCT, skeletal dysplasia, keratan sulfate

ObjectivesThis 109-week, nonrandomized, observational study of mucopolysaccharidosis II (MPS II) patients already enrolled in the Hunter Outcome Survey (HOS) (NCT00882921), assessed the long-term immunogenicity of idursulfase, and examined the effect of idursulfase-specific antibody generation on treatment safety (via infusion-related adverse events [IRAEs]) and pharmacodynamics (via urinary glycosaminoglycans [uGAGs]).MethodsMale patients ≥ 5 years, enrolled in HOS regardless of idursulfase treatment status were eligible. Blood/urine samples for anti-idursulfase antibody testing and uGAG measurement were collected every 12 weeks.ResultsDue to difficulties in enrolling treatment-naïve patients, data collection was limited to 26 enrolled patients of 100 planned patients (aged 5.1-35.5 years) all of whom were non-naïve to treatment. Fifteen (58%) patients completed the study. There were 11/26 (42%) seropositive patients at baseline (Ab +), and 2/26 (8%) others developed intermittent seropositivity by Week 13. A total of 9/26 patients (35%) had ≥ 1 sample positive for neutralizing antibodies. Baseline uGAG levels were low due to prior idursulfase treatment and did not change appreciably thereafter. Ab + patients had persistently higher uGAG levels at entry and throughout the study than Ab - patients. Nine of 26 (34%) patients reported IRAEs. Ab + patients appeared to have a higher risk of developing IRAEs than Ab - patients. However, the relative risk was not statistically significant and decreased after adjustment for age.Conclusions50% of study patients developed idursulfase antibodies. Notably Ab + patients had persistently higher average uGAG levels. A clear association between IRAEs and antibodies was not established.

Characteristic cardiac valve abnormalities and left ventricular hypertrophy are present in untreated patients with mucopolysaccharidosis type VI (MPS VI). Cardiac ultrasound was performed to investigate these findings in subjects during long-term enzyme replacement therapy (ERT) with recombinant human arylsulfatase B (rhASB, rhN-acetylgalactosamine 4-sulfatase, galsulfase, Naglazyme®). Studies were conducted in 54 subjects before ERT was begun and at specific intervals for up to 96 weeks of weekly infusions of rhASB at 1 mg/kg during phase 1/2, phase 2, and phase 3 trials of rhASB. At baseline, mitral and aortic valve obstruction was present and was significantly greater in those ≥12 years of age. Mild mitral and trace aortic regurgitation were present, the former being significantly greater in those

This article provides an update on a two-part international observational registry called AADCAware, which focuses on individuals with aromatic L-amino acid decarboxylase deficiency (AADCd). AADCd is a rare neurodevelopmental disorder that causes severe impairment. Part A of the registry examines the natural history of AADCd in patients receiving standard care, while Part B assesses the long-term safety and efficacy of a specific treatment called eladocagene exuparvovec on motor function. The study found that the majority of subjects failed to achieve major motor milestones, indicating a significant need for daily life support. [Extracted from the article]