IDIOPATHIC DILATED CARDIOMYOPATHY - FAMILIAL PREVALENCE AND HLA DISTRIBUTION

Objectives-To compare HLA distribution in familial and non-familial di lated cardiomyopathy, because a serum marker that could identify famil ies at risk of developing dilated cardiomyopathy should be of use in s creening for the disease. Patients-100 patients with dilated cardiomyo pathy. Methods-200 first degree relatives from 56 of the proband famil ies were screened for dilated cardiomyopathy by echocardiography. The HLA profile of the patients with dilated cardiomyopathy, as well as of the familial and non-familial subgroups, was compared with that of 90 00 normal controls. Results-The familial prevalence of dilated cardiom yopathy in this patient Methods group was ''definite'' in 14 of 56 (25 %) and PATIENTS ''possible'' in 25 of 56 (45%). The HLA-DR4 frequency in the 100 patients with dilated cardiomyopathy was similar to that in the 9000 controls (39% v 32%). However, the DR4 subtype was significa ntly more common in the 25 probands with a familial tendency to dilate d cardiomyopathy than in the 31 probands with non-familial dilated car diomyopathy (68% v 32%; P < 0.05). Conclusions-The present finding sup ports an HLA linked predisposition to familial dilated cardiomyopathy. The HLA type DR4 was significantly more common in familial than in no n-familial cases. The DR4 halotype was associated with two thirds of t he families at risk for dilated cardiomyopathy.