[Confirming the cause of inherited chronic chorea in Chinese patients].

OBJECTIVE

Huntington's disease (HD, known as inherited chronic chorea in China) is an autosomal dominant disorder. Almost all of the cases of inherited chronic chorea reported in the chinese literature were sporadic while about one-third of the HD families in foreign reports were related. To find out whether the gene defect responsible for inherited chronic chorea in Chinese is the same as that for Huntington's disease in Caucasians.

METHOD

PCR method was employed to amplify the (CAG)n repeat sequence of the IT15 gene in normal Chinese and members of the families suffering from inherited chronic chorea in Chinese.

RESULTS

The copy number of the repeats varied from 16 to 26 in 25 normal Chinese and increased significantly from 44 to 53 in 7 affected members from 4 families.

CONCLUSION

It was confirmed for the first time at the gene level that the mechanism for inherited chronic chorea in Chinese is the same as that for Huntington's disease in Caucasians.