FINE LOCALIZATION OF THE TORSION DYSTONIA GENE (DYT1) ON HUMAN-CHROMOSOME 9Q34 - YAC MAP AND LINKAGE DISEQUILIBRIUM

The DYT1 gene, which maps to chromosome 9q34, appears to be responsibl e For most cases of early-onset torsion dystonia in both Ashkenazic Je wish (AJ) and non-Jewish families. This disease is inherited in an aut osomal dominant mode with reduced penetrance (30%-40%). The abnormal i nvoluntary movements associated with this disease are believed to be c aused by unbalanced neural transmission in the basal ganglia. Previous linkage disequilibrium studies in the Al population placed the DY71 g ene in a 2-cM region between the loci D9S62a and ASS. A YAC contig has now been created spanning 600 kb of this region including D9S62a. The location of the DYT1 gene has been refined within this contig using s everal new polymorphic loci to expand the linkage disequilibrium analy sis of the AJ founder mutation. The most likely location of the DYT1 g ene is within a 150 kb region between the loci D9S2161 and DPS63.