HLA gene analysis in a Japanese family with hypertrophic cardiomyopathy by restriction fragment length polymorphism.

A large Japanese family with hypertrophic cardiomyopathy (HCM) was examined (n = 61). Ten of 14 affected family members who showed HCM on the basis of electrocardiography and two-dimensional echocardiography were subjected to human leukocyte antigen (HL-A)-A,B,C typing by the lymphocyte cytotoxicity test and D, DR typing by restriction fragment length polymorphism (RFLP). As control, the HLA genotype of 14 non-affected family members was analyzed. HLA typing of the affected subjects with HCM revealed a very close association (67%) of HLA-DR (4w8) among A,B,C,D and DR. However, the LOD scores of HLA-DR4 and -DR w8 were 0.693 (theta = 0.35) and 0.642 (theta = 0.30) respectively. These data suggest that HLA-loci, analyzed on the basis of RFLP, may not be related with familial HCM with or without obstruction.