Mutations of the Wilson disease (WD) gene were studied in patients from Bashkortostan. Four mutations were identified: His1069Gln, 3402delC, Glu1064Lys, and 3559 + 1G-->T. The latter mutation was described for the first time. Mutation His1069Gln was found to be the most prevalent in Bashkortostan; its frequency was 43.5%. The associations of the mutations found with the haplotypes for polymorphic loci D13S316, D13S133, and D13S228 were studied. The mutations were found to be linked with specific haplotypes, and the study of polymorphic haplotypes can therefore facilitate the search for mutations in the gene for WD. The results of the molecular genetic study of WD can be used for direct and indirect DNA diagnostics of this disease in Bashkortostan.