FAMILIAL DILATED CARDIOMYOPATHY IN THE UNITED-KINGDOM

Objectives-To determine the frequency and mode of inheritance of famil ial dilated cardiomyopathy in the United Kingdom. Background-Two recen t prospective studies have suggested that familial forms of dilated ca rdiomyopathy are common but have been limited by selective screening m ethods, inadequate diagnostic criteria, and low rates of ascertainment . Methods-Prospective screening study of 236 relatives from 40 familie s of patients with dilated cardiomyopathy. Screening consisted of clin ical examination, 12 lead electrocardiogram, and two-dimensional Doppl er echocardiography. Relatives with systemic hypertension and other ca rdiac diseases were excluded from the study. All echocardiograms were performed by an experienced echocardiographer who was blinded to clini cal information. Relatives were classified as having dilated cardiomyo pathy, left ventricular enlargement (method of Henry), depressed fract ional shortening, or as being normal. Relatives with abnormal investig ations underwent further evaluation as appropriate. Results-Twenty fiv e cases of dilated cardiomyopathy were identified and came from 10 (25 %) of the 40 families screened. Pedigree analysis was most consistent with inheritance and (65-95%). Of the remaining apparently healthy rel atives, 37 (18%) were found to Methods have left ventricular enlargeme nt and PATIENTS nine (4%) depressed fractional shortening; these value s were significantly higher than those observed in 239 healthy control s (24 (10%), P = 0.02 and one (0.4%), P = 0.01, respectively). Conclus ions-Patients with dilated cardiomyopathy commonly have an affected fa mily member and a high proportion of apparently healthy relatives with minor echocardiographic abnormalities. Segregation analysis suggests that familial dilated cardiomyopathy is the result of the transmission of a rare autosomal dominant gene. Further studies are currently unde rway to characterise the molecular basis of cardiomyopathy and disease within these families.