ian language) Muslims (Sunni), six endogamous Hindu castes, and a tribal ethnic group (Irulars) using 13 CODIS (Combined DNA Index System) autosomal microsatellite markers. Muslims show the highest average heterozygosity (0.405) compared to the other groups. The neighbor-joining tree and the multidimensional-scaling plot show clustering of Tamil-speaking Muslims with three caste groups (Gounder, Paraiyar, and Vanniyar), whereas the Irular tribe is separated out of the cluster.

摘要

Fragile X syndrome is the most common form of inherited mental retardation. The molecular basis is usually the unstable expansion of a CGG repeat in the FMR1 gene. We previously analyzed a sample of two Basque valleys. In the present work we extend the study to another five isolated valleys. The results show that differences in factors implicated in CGG repeat instability--CGG repeat size, XS548/FRAXAC1 haplotypes, and AGG interspersion pattern-are present in the Basque populations analyzed.