Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS): High-resolution physical and transcript map of the candidate region in chromosomeregion 13q11

Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS or SAGS) is a neurodegenerative disease frequent in northeastern Quebec. In a previo us study, we localized the disease gene to chromosome region 13q11 by ident ifying excess sharing of a marker allele in patients followed by Linkage an alysis and haplotyping. To create a detailed physical map of this region, w e screened CEPH mega-YACs with 41 chromosome 13 sequence-tagged-sites (STSs ) known to map to 13q11-q12. The YAG contig, composed of 27 clones, extends on the genetic map from D13S175 to D13S221, an estimated distance of at le ast 19.3 cM. A high-resolution BAC and PAC map that includes the ARSACS cri tical region flanked by D13S1275 and D13S292 was constructed. These YAC and BAC/PAC maps allowed the accurate placement of 29 genes and ESTs previousl y mapped to the proximal region of chromosome 13q. We confirmed the positio n of two candidate genes within the critical region and mapped the other 27 genes and ESTs to nearby intervals. Six BAC/PAC clones form a contig betwe en D13S232 and D13S787 for sequencing within the ARSACS critical region. (C ) 1999 Academic Press.