Mucopolysaccharidosis in Children: Clinical and Genetic Insights from Southwestern Colombia

Abstract

Introduction: Mucopolysaccharidoses (MPS) are rare hereditary lysosomal storage disorders that predominantly affect the pediatric population. They are caused by specific enzymatic deficiencies that impair the degradation of glycosaminoglycans (GAGs), leading to their accumulation in tissues and resulting in multisystemic manifestations. The aim of this study was to describe the clinical and molecular characteristics of pediatric patients with MPS treated between 2019 and 2024 at a referral center in Cali, Colombia. Materials and Methods: We conducted an observational, descriptive, cross-sectional study. A total of 41 patients under 18 years of age with a confirmed diagnosis by enzymatic assay and/or molecular testing were included. Clinical and laboratory data were collected from medical records and analyzed using descriptive statistics. Results: The median age at onset was 1 year (IQR: 1–10); 53.7% were female, and most were from the Valle del Cauca region. The most frequent clinical findings were facial dysmorphism, musculoskeletal involvement, intellectual disability, and valvular heart disease. The most common MPS subtype was type VI (39%), followed by type IV-A (34.1%), type II (17.1%), and type I (7.3%). Elevated urinary GAGs were found in 85.4% of cases, and enzymatic deficiency in 92.7%. Genetic variants were identified in 65.8%, with GALNS, IDS, and ARSB being the most frequent genes. Enzyme replacement therapy was administered to 87.8% of patients. Conclusions: The findings indicate appropriate clinical and enzymatic diagnostic approaches, though genetic diagnosis remains an area for improvement. The subtype distribution differs from international reports, and disparities in access to specialized care were noted.