Frequency and clinical genetics of familial dilated cardiomyopathy in Cape Town: Implications for the evaluation of patients with unexplained cardiomyopathy
South African Medical Journal
Cardiac Clinic and Cardiovascular Genetics Laboratory, Hatter Institute for Cardiovascular Research in Africa, Department of Medicine Groote Schuur Hospital and University of Cape Town, South Africa; College of Medicine, King Saud Bin Abdelaziz University of Medical Sciences, Riyadh, Saudi Arabia; Division of Human Genetics, Departments of Clinical Laboratory Sciences and Medicine, University of Cape Town, South Africa
Background. Studies from Europe and North America suggest that 20 - 50% of patients with dilated cardiomyopathy (DCM) may have familial disease. There is little information on the frequency and clinical genetics of familial DCM in Africa. Purpose. To determine the frequency and probable mode of inheritance of familial DCM in patients referred for investigation of the cause of DCM at a tertiary centre in Cape Town. Methods. We conducted a retrospective analysis of consecutive patients diagnosed with DCM between 1 February 1996 and 31 December 2009 to determine the frequency of familial disease. Results. Of 109 unrelated patients with DCM, 29 (26.6%) had familial disease. Their mean age of onset of cardiomyopathy (28.01 (standard deviation (SD) 15.33) years) was significantly younger than that for non-familial cases (39.1 (SD 12.6) years) (p=0.001). Male predominance (N=21, 72.4%) and racial distribution (15 (48.3%) coloured patients, 10 (34.5%) black Africans, 4 (13.8%) white individuals, and 1 (3.4%) of Indian descent) of familial DCM probands were similar to the non-familial cases. Of the 29 patients with familial DCM, 2 (7%) had at least one relative diagnosed with peripartum cardiomyopathy. Pedigree analysis of the 29 families was consistent with autosomal dominant inheritance in 72.4%, autosomal recessive inheritance in 17.2% and X-linked recessive inheritance in 10.4%. Conclusions. Familial DCM affects at least a quarter of African patients with DCM, presents at a young age, is associated with peripartum cardiomyopathy, and follows an autosomal dominant pattern of inheritance in the majority of families. Family screening for familial DCM is indicated in all cases of unexplained DCM, including patients with peripartum cardiomyopathy.
adult; article; autosomal dominant inheritance; autosomal recessive inheritance; clinical genetics; congestive cardiomyopathy; controlled study; electrocardiogram; familial disease; female; heart catheterization; heart left ventricle ejection fraction; heart left ventricle function; human; major clinical study; male; patient referral; pedigree analysis; peripartum cardiomyopathy; race difference; retrospective study; tertiary health care; Adult; African Continental Ancestry Group; Cardiomyopathy, Dilated; Female; Humans; Male; Pedigree; Peripartum Period; Pregnancy; Pregnancy Complications; Retrospective Studies; South Africa