Alpha-adducin polymorphism in hypertensives of South African ancestry

The alpha-adducin gene contributes significantly to hypertension in MHS rats (rats of the Milan hypertensive strain) and in some white and Japanese populations, causing a low renin, sodium, and diuretic-sensitive hypertension. No data are available from populations of African ancestry who have a high prevalence of low renin, sodium, and diuretic-sensitive hypertension. We studied the relationship between the 460-Trp variant of alpha-adducin gene with hypertension using a case-control study design in black South Africans. Surprisingly we found that the overall frequency of the 460-Trp allele was low (approximately 6%), but in spite of such relatively low frequency, the 460-Trp allele was 2.5-fold more frequent in hypertensives than normotensives (P = .028), with an odds ratio for hypertension associated to the state of carrier of at least one 460-Trp allele of 2.68. The finding of such low frequency of the 460-Trp allele in individuals of African ancestry points to the substantial ethnic variability of the genes that have been found to be associated with hypertension. On the other hand, it suggests an association of the 460-Trp allele with hypertension also in subjects of African origin.