Molecular Analysis of 9 Unrelated Families Presenting With Juvenile and Chronic GM1 Gangliosidosis

Abstract GM1 gangliosidosis is a rare autosomal recessive lysosomal storage disorder with high prevalence in Brazil (1:17 000). In the present study, we genotyped 10 individuals of 9 unrelated families from the States of São Paulo and Minas Gerais diagnosed with the juvenile and chronic forms of the disease. We found the previously described p.Thr500Ala mutation in 8 alleles; c.1622-1627insG and p.Arg59His in 2 alleles (the latter also segregating with c.1233+8T>C); and p.Phe107Leu, p.Leu173Pro, p.Arg201His, and p.Gly311Arg in 1 allele each. Two mutations (p.Ile354Ser and p.Thr384Ser) and 1 neutral alteration (p.Pro152=) are described for the first time. All patients presented as compound heterozygotes. A discussion on genotype-phenotype correlation is also presented.