To identify genetic factors in the immune system which control the susceptibility to dilated cardiomyopathy (DCM), HLA class II DNA typing was performed in 61 Japanese patients, using PCR/SSO probe analyses. The frequencies of HLA-DQB1∗0503 (15% vs 5%; RR=3.06, X2=7.19) and DQB1∗0604 (21% vs 10%; RR=2.41, X2=6.20) were significantly increased and that of HLA-DQB1∗0502 (RR=1.74) was slightly increased in the DCM patients. The frequency of DQB1∗0303 (16% vs 31%; RR=0.44, X2=5.16) was significantly decreased in the patients. The increased HLA-DQB1 alleles have a histidine residue in common at the 30th codon for the HLA-DQB1 chain. Among the genetic markers studied by Southern blot analyses, IGLV (immunoglobulin lambda light chain, pV3.3) showed a strong association with DCM, i.e. A2/A2 genotype was found in 37.7% of patients whereas it was observed in only 18.9% of the control subjects (RR=2.6, X2=7.77). The frequency of this genotype was higher in patients under age 45 years at the time of diagnosis (45.5%, RR=3.6, X2=10.02). These results suggest that HLA and immunoglobulin genes are closely linked to susceptibility to DCM.
All Science Journal Classification (ASJC) codes
- Cardiology and Cardiovascular Medicine