EC Neurology

Background: GM1-gangliosidosis is a rare autosomal recessive disorder caused by mutations in the GLB1 gene and resultant functional deficiency of the lysosomal enzyme acid β-galactosidase with accumulation of keratan sulphate, glycolipids, and GM1 gangliosides in tissues.

Case Presentation: A 9-month-old male child with moderate hepatosplenomegaly, central hypotonia, a large Mongolian spot on the back and delayed verbal and motor milestones; based on clinical suspicion, through history, examination and MRI brain findings; was subjected to clinical genome sequencing. A novel homozygous missense variant (c.326G>C) in exon 3 of the GLB1 gene (NM_000404.3) that results in the amino acid substitution from arginine to proline at codon 109 (p.Arg109Pro) was identified.

Conclusion: The novel GLB1 mutation identified in this study will help to expand the spectrum of known GLB1 mutations and will be helpful in genetic counselling.

 Keywords: Novel GLB1 Mutation; GM1 Gangliosidosis; Central Hypotonia; Genome Sequencing; β-Galactosidase

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