Extensive mongoloid spots in mucopolysaccharidosis Type I Hurler syndrome

Abstract

Lysosomal storage diseases are inherited metabolic disorders that are caused by enzyme deficiencies within the lysosomes. The most common lysosomal storage disorder associated with Mongolian spots (MSs) is GM1 gangliosidosis Type-1. We are reporting a case of Hurler disease with extensive MS. A 9-month-old girl, born to a consanguineously married couple, presented with a developmental delay with uneventful birth history. The presence of multiple mongoloid spots over the lumbosacral region and lateral abdominal wall was noticed since birth. Examination showed coarse facies with a depressed nasal bridge and a low-set ear. Multiple mongoloid macules were noted in the lumbosacral region. Serum enzyme assay level had decreased activity of alpha-L-iduronidase (IDUA). Exome sequencing revealed a homozygous mutation in exon 8 of the IDUA gene. Extensive MS can be seen in mucopolysaccharidosis (MPS) Type 1 in addition to commonly described GM1 gangliosidosis. The early diagnosis helps to start enzyme replacement therapy in MPS Type I, compared to currently no specific treatment available for GM1 gangliosidosis.