Localization of the autosomal dominant HLA-linked spinocerebellar ataxia (SCA1) locus, in two kindreds, within an 8-cM subregion of chromosome 6p.

Abstract

Two large kindreds with HLA-linked, autosomal dominant spinocerebellar ataxia (SCA1) were examined with markers from chromosome 6p to determine the location of the SCA1 locus. Results of the three-point analysis between the markers HLA-A, SCA1, and F13A overwhelmingly favor the conclusion that SCA1 is located distal of HLA and proximal of F13A. In addition, our data strongly support the conclusion that SCA1 lies centromeric and genetically very close to the highly informative D6S89 marker within the 8-cM chromosomal segment flanked by the D6S88 and D6S89 markers. In the two kindreds, one recombinant was observed between D6S89 and SCA1, resulting in a recombination fraction of .014 between the two loci.