Familial Dilated Cardiomyopathy

To the Editor: The well-designed study by Michels et al. (Jan. 9 issue)¹ provides further evidence that the percentage of patients with idiopathic dilated cardiomyopathy who have familial disease is higher than previously thought. It should be noted, however, that all but one of the index patients in this series of patients from the Mayo Clinic were white.¹ Epidemiologic studies have suggested that blacks may be at increased risk for idiopathic dilated cardiomyopathy, although few genetic studies of this disease have been undertaken in multiracial populations.^{2 , 3} In a recent case–control study of idiopathic dilated cardiomyopathy in Baltimore, a roughly threefold…