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Abstract Background Alpha-mannosidosis is a lysosomal storage disorder caused by reduced enzymatic activity of alpha-mannosidase. SPARKLE is an alpha-mannosidosis registry intended to obtain long-term safety and effectiveness data on the use of velmanase alfa during routine clinical care in patients with alpha-mannosidosis. It is a post-approval commitment to European marketing authorization for Velmanase alfa (Lamzede®), the first enzyme replacement therapy for the treatment of non-neurologic manifestations in patients with mild to moderate alpha-mannosidosis. In addition, SPARKLE will expand the current understanding of alpha-mannosidosis by collecting data on the clinical manifestations, progression, and natural history of the disease in treated and untreated patients, respectively. Results The SPARKLE registry is designed as a multicenter, multinational, noninterventional, prospective cohort study of patients with alpha-mannosidosis, starting patient enrollment in 2020. Patients will be followed for up to 15 years. Safety and effectiveness as post-authorization outcomes under routine clinical care in patients with treatment will be evaluated. The primary safety outcomes are the rate of adverse events (anti-velmanase alfa-immunoglobulin G antibody development, infusion-related reactions, and hypersensitivity). Secondary safety outcomes include the evaluation of medical events, change in vital signs, laboratory tests, physical examination, and electrocardiogram results. The primary effectiveness outcome is a global treatment response rate, evaluated as the individual aggregate of single endpoints from pharmacodynamic, functional, and quality-of-life effectiveness outcomes; secondary effectiveness outcomes are to characterize the population of patients with alpha-mannosidosis with regard to clinical manifestation, progression, and natural history of the disease. Any patient in the European Union with a diagnosis of alpha-mannosidosis who is willing to participate will likely be eligible for inclusion in the registry. Publications to disseminate scientific insights from the registry are planned. Conclusion This study will provide real-world data on the long-term safety and effectiveness of velmanase alfa in patients with alpha-mannosidosis during routine clinical care and increase the understanding of the natural course, clinical manifestations, and progression of this ultra-rare disease.

Abstract Background Mucopolysaccharidosis (MPS) type III (Sanfilippo syndrome) comprises a group of rare, lysosomal storage diseases caused by the deficiency of one of four enzymes involved in the degradation of heparan sulfate. The clinical hallmark of the disease is severe neurological deterioration leading to dementia and death in the second decade of life. Adult MPS patients are generally of short stature. To date there is no clear description of the physical development of MPS III patients. The aim of this study was to document growth reference data for MPS III patients. We collected growth data of 182 German MPS III patients and were able to develop growth charts for this cohort. Growth curves for height, weight, head circumference, and body mass index were calculated and compared to German reference charts. Results Birth height, weight and head circumference were within the physiological ranges. Both genders were significantly taller than healthy children at 2 years of age, while only male patients were taller at the age of four. Growth velocity decelerated after the ages of 4.5 and 5 years for female and male patients, respectively. Both genders were significantly shorter than the reference group at the age of 17.5 years. Head circumference was larger compared to healthy matched controls within the first 2 years of life and remained enlarged until physical maturity. Conclusion MPS III is a not yet treatable severe neuro-degenerative disease, developing new therapeutic strategies might change the course of the disease significantly. The present charts contribute to the understanding of the natural history of MPS III. Specific growth charts represent an important tool for families and physicians as the expected height at physical maturity can be estimated and therapeutic effects can be monitored.

Background: Mucopolysaccharidosis type IIIA (MPS IIIA, Sanfilippo A syndrome) is a chronic progressive neurodegenerative storage disorder caused by a deficiency of lysosomal sulfamidase. The clinical hallmarks are sleep disturbances, behavioral abnormalities and loss of cognitive, speech and motor abilities. Affected children show developmental slowing from the second year of life, dementia occurs by the age of 5 years followed by death in the second decade of life. Only a few studies concerning HSCT in MPS IIIA have been published and do not document a clear benefit of treatment. Methods: The present study summarizes the clinical outcome of a girl with MPS IIIA who received HSCT at the age of 2.5 years. Her clinical course was compared with the natural history of six untreated MPS IIIA patients carrying the same mutations (p.R74C and p. R245H) in the SGSH-gene. Results: Eight years after successful HSCT, the patient showed a global developmental delay. However, cognitive abilities continued to develop, albeit very slowly. There was no sign of regression. She could talk in short sentences, had good motor abilities and performed basic daily living activities by herself. She did not present with sleeping problems, but behavioral abnormalities were profound. In contrast, the six untreated patients with identical mutations in the SGSH-gene showed the typical progressive course of disease with early and continuous loss of abilities. Conclusions: The present data suggest a beneficial effect of HSCT performed at an early stage of MPS IIIA on cognitive skills, motor function and quality of life.