A Child Presenting with Mucopolysaccharidosis

The lysosomal storage disorders are a group of diseases that are typified by an accumulation of waste products in the lysosomes. Mucopolysaccharidoses are lysosomal storage disorders due to diverse lysosomal enzyme deficiencies. Ms HT was 2 years and 5 months old when she presented to our metabolic bone clinic with clinical features that were suggestive of a genetic syndrome that was associated with a metabolic bone disease. The urine GAG spot test was positive. The MPS screen identified a reduction in arylsulfatase B activity and sequencing of the ARSB gene detected a pathogenic variant, in keeping with Maroteaux-Lamy syndrome. The diagnosis of MPS is confirmed by urine GAG, enzyme activity analysis and genetic testing. The available treatments include hematopoietic stem cell transplantation, enzyme replacement therapy and surgery. MPSs are heterogeneous, progressive, multisystem diseases for which diagnosis is often delayed. Greater awareness of MPS will enable early diagnosis and treatment. Treatment is however costly and is frequently unavailable to patients in the public sector.