Genotypic and phenotypic characterization of Brazilian patients with GM1 gangliosidosis.

[gm1 gangliosidosis]

GM 1 gangliosidosis is a lysosomal disorder caused by β-galactosidase deficiency due to mutations in the GLB 1 gene . It is a rare neurodegenerative disorder with an incidence of about 1 :100 ,000 -1 :200 ,000 live births worldwide . Here we review GLB 1 mutations and clinical features from 65 Brazilian GM 1 gangliosidosis patients . Molecular analysis showed 17 different mutations and c .1622 -1627 insG was the most frequent , accounting for 50 % of the alleles . Cognitive impairment was the main clinical sign , observed in 82 % of patients , followed by hepatosplenomegaly observed in 56 % of patients . It was possible to establish a significant correlation between age at onset of symptoms preceding the first year of life and the presence of the mutation c .1622 -1627 insG (p =0 .03 ). Overall our findings differ from literature and represent the exclusive genotypic profile found in Brazilian GM 1 gangliosidosis patients .