High prevalence of diabetes mellitus in a five-generation Chinese family with Huntington's disease.

Huntington's disease (HD) is associated with diabetes mellitus (DM) in population studies, but no case has been reported in a large HD family. We report a case of a five-generation Chinese family who is afflicted by both HD and DM. The prevalence of DM in HD of this family was high (72.7%). The diagnosis of HD in 11 family members was confirmed by the genetic test of the proband who had 42 CAG repeats. Furthermore, the proband's daughter had abnormal locus at G3460T in MT-ND1 among mtDNA genome. Our case report suggests a genetic link between HD and DM.