[Studies on the genetic susceptibility to dilated cardiomyopathy]

HLA-DQB1,-DRB1 genes of 27 Chinese patients with dilated cardiomyopathy (DCM), 7 high risk individuals in a DCM kindred and 17 normal control subjects were analysed with the use of restriction fragment length polymorphisms (RFLP) with full length DQB1 and DRB1 cDNA probes according to the standard and nomenclature of the Xth International Histocompatibility Workshop. The resulting restriction patterns allowed genotyping of HLA-DR and HLA-DQw. D-DQw8 frequency increased significantly in patients with DCM as compared with that of the controls (P < 0.05). D-DQw4 also increased in patients although no statistical significance was shown when Chi-square value was corrected with Yate's correction, whereas D-DQw5 overrepresented in controls (P < 0.05). Over half of the high risk individuals (4/7) in the familial DCM kindred carry D-DQw8 and D-DQw4. These results support the hypothesis that HLA class II genes were associated with an increased risk for DCM, HLA-DQB rather than -DRB may confer genetic susceptibility to DCM.