SACS and spastic ataxia: A compelling positional and functional candidate gene, sacsin molecular chaperone (SACS, spastic ataxia of Charlevoix-Saguenay), positioned from 15.21 to 15.30 Mb, was located within the 27.74 Mb extended haplotype, and just upstream from the 3.3 Mb homozygosity-mapping haplotype (Supplemental Fig. 2).