HL-A and hypertrophic cardiomyopathy.

HL-A antigens were determined in 26 unrelated Japanese patients with hypertrophic cardiomyopathy. Several antigens were more common in patients compared with controls, but statistically significant differences were not evidenced. We also studied two families in which many had a hypertrophic cardiomyopathy. All the affected individuals revealed HL-A-A9 and B7, while none among the unaffected family members had HL-A-B7. Our findings suggest that the HLA-A system may play some role in the pathogenesis of hypertrophic cardiomyopathy with familial occurrence.