ASSOCIATION OF ANGIOTENSIN-II TYPE-1 RECEPTOR GENE POLYMORPHISM WITH ESSENTIAL-HYPERTENSION

The renin-angiotensin system is involved in control of blood pressure and salt and fluid homeostasis. Genes for components of this system ha ve been of major focus in research on the causation of the common, com plex, polygenic trait, essential hypertension (HT). Association of an A-->C variant at nucleotide 1166 of the angiotensin II type 1 receptor (AT(1)R) gene with HT, but an absence of linkage of this locus with t his disease, has been reported recently. Since cofirmation in a differ ent setting is imperative, we performed a cross-sectional case-control study of the Al166C variant in a well-characterized group of 108 Cauc asian HT subjects with a strong family history (two affected parents) and early onset disease. Genotyping was by mismatch polymerase chain r eaction/BfrI restriction fragment length polymorphism analysis. Freque ncy of the C-1166 allele was 0.40 in HTs and 0.29 in normotensives. Th e difference in genotype (chi(2) = 13, P = 0.0015) and allele (chi(2) = 5.3, P = 0.02) frequencies between the two groups was significant (o dds ratio for CC vs AA + AC = 7.3 [95% CI, 1.9-31.9). The present resu lts implicate the AT(1)R gene, or a locus in linkage disequilibrium wi th the variant tested, in the causation of essential HT.