Long-term impact of early initiation of enzyme replacement therapy in 34 MPS VI patients: A resurvey study.

Patients with mucopolysaccharidosis type VI (MPS VI) present with a wide range of disease severity and clinical manifestations, with significant functional impairment and shortened lifespan. Enzyme replacement therapy (ERT) with galsulfase has been shown to improve clinical and biochemical parameters including patient survival, quality of life and growth. The present study is a resurvey of 34 Brazilian MPS VI patients with rapidly progressive disease (classical phenotype) who initiated ERT with galsulfase under five years of age and had been on ERT until data collection in 2019, with few exceptions (n = 4 patients who died before 2019). Anthropometric measures, urinary glycosaminoglycans, and data regarding cardiac, orthopedic, neurologic, sleep apnea, hearing and ophthalmologic outcomes were filled in by specialists. Pubertal development, clinical complications, hospitalizations, and surgeries were also assessed. In this resurvey study, treatment with galsulfase has shown to be safe and well tolerated in MPS VI patients who initiated ERT under the age of 5 years and who have been undergoing ERT for approximately 10 years. Mortality rate suggests that early initiation of ERT may have a positive impact on patients' survival, improving but not preventing disease progression and death. MPS VI patients on ERT also showed improved growth velocity and the pubertal development was normal in all surviving patients. Follow-up data on pneumonia and hospitalization suggest that early ERT may have a protective effect against major respiratory complications. Cardiac valve disease progressed since their prior evaluation and spinal cord compression was observed in a large number of patients, suggesting that these disease complications were not modified by ERT.

A decade of molecular diagnosis of Mucolipidosis II and III in Brazil: a pooled analysis of 32 patients

Abstract GlcNAc-1-phosphotransferase is a hexameric complex formed by subunits α, β, and γ, where the first two are encoded by the GNPTAB gene and the third by the GNPTG gene. Pathogenic variants identified in the GNPTAB gene cause the diseases Mucolipidosis II and III alpha/beta, which are severe and characterized by an overflow of lysosomal hydrolases into the extracellular environment, and their absence in lysosomal compartments causes an accumulation of non-degraded macromolecules. Methodology: a retrospective study that included 32 unrelated Brazilian patients with a clinical and genetic diagnosis of Mucolipidosis II/III alpha/beta. The regional frequency of the altered alleles was determined. Results: The patients were from all regions of Brazil. The most prevalent variants were c.3503_3504del, associated with the severe form of the disease, and c.1208T>C, associated with the milder form. Variant c.3503_3504del is the most frequently found in the Midwest, Northeast, and Southeast regions of Brazil. In the South, 42.8% of the alleles present the c.1196C>T variant. Conclusions: From the perspective of all patients diagnosed with Mucolipidosis II/III in Brazil, it is possible to conclude that different regions present allelic frequencies of specific pathogenic variants, which can be explained by the occurrence of a founding effect or high inbreeding rates.

Enzyme replacement therapy with galsulfase in 34 children younger than five years of age with MPS VI.

BACKGROUND: Mucopolysaccharidosis type VI (MPS VI) is a progressive, chronic and multisystem lysosomal storage disease with a wide disease spectrum. Clinical and biochemical improvements have been reported for MPS VI patients on enzyme replacement therapy (ERT) with rhASB (recombinant human arylsulfatase B; galsulfase, Naglazyme®, BioMarin Pharmaceutical Inc.), making early diagnosis and intervention imperative for optimal patient outcomes. Few studies have included children younger than five years of age. This report describes 34 MPS VI patients that started treatment with galsulfase before five years of age. METHODS: Data from patients who initiated treatment at <5 years of age were collected from patients' medical records. Baseline and follow-up assessments of common symptoms that led to diagnosis and that were used to evaluate disease progression and treatment efficacy were evaluated. RESULTS: A significant negative correlation was seen with treatment with ERT and urinary GAG levels. Of those with baseline and follow-up growth data, 47% remained on their pre-treatment growth curve or moved to a higher percentile after treatment. Of the 9 patients with baseline and follow-up sleep studies, 5 remained unaffected and 1 patient initially with mild sleep apnea showed improvement. Data regarding cardiac, ophthalmic, central nervous system, hearing, surgical interventions and development are also reported. No patient discontinued treatment due to an adverse event and all that were treatment-emergent resolved. CONCLUSIONS: The prescribed dosage of 1mg/kg IV weekly with galsulfase ERT is shown to be safe and effective in slowing and/or improving certain aspects of the disease, although patients should be closely monitored for complications associated with the natural history of the disease, especially cardiac valve involvement and spinal cord compression. A long-term follow-up investigation of this group of children will provide further information on the benefits of early treatment as well as disease progression and treatment efficacy and safety in this young patient population.

Splenopancreatic field abnormality is not unique to trisomy 13.

Splenopancreatic fusion is an uncommon finding, usually only seen as part of the splenopancreatic field abnormality associated with trisomy 13. It may present itself either as ectopic splenic tissue in the cauda pancreatis, as ectopic pancreatic tissue in the spleen or accessory spleen, or as fusion of the cauda pancreatis and splenic hilum. In this study, we report four unrelated congenital anomaly cases presenting trisomy 21, osteocraniostenosis syndrome, isolated congenital heart defect, and oligohydramnios sequence due to prune belly syndrome, in which fusion was observed. This demonstrates that, although it may be more common in trisomy 13, this phenomenon should not be interpreted as pathognomonic to that syndrome.