-344C/T polymorphism of CYP11B2 gene in Italian patients with idiopathic low renin hypertension

Most patients with low renin essential hypertension are not qualitatively d ifferent from patients with idiopathic hyperaldosteronism. as in both condi tions aldosterone secretion is not appropriately reduced. The aim of the st udy was to investigate allele and genotype frequencies of the -344C/T polym orphism, located in the promoter region of the aldosterone synthase gene, i n 83 patients with idiopathic low renin hypertension characterized by an in creased aldosterone to renin ratio, including both patients with low renin essential hypertension (n = 53) and subjects with idiopathic hyperaldostero nism (n = 30), compared with 78 patients with normal to high renin essentia l hypertension and 126 normotensive control subjects. The relationship of - 344C/T genotypes to basal and post-captopril plasma aldosterone/plasma reni n activity ratio was also examined in the entire hypertensive population. A n increased frequency of the T allele and a relative excess of TT homozygos ity over CC homozygosity were found in patients with idiopathic low renin h ypertension in comparison with both normal to high renin hypertensives and normotensive controls. A higher post-captopril aldosterone to renin ratio w as found in the hypertensives with TT genotype than in those with CC genoty pe, and TT+TC genotypes were associated with a smaller decrease in the aldo sterone-to-renin ratio elicited by captopril administration. The present st udy suggests that the -344C/T polymorphism, or a functional variant in link age disequilibrium with it, may play a role in the abnormal regulation of a ldosterone secretion in idiopathic low renin hypertension. Am J Hypertens 2 001;14:934-941 (C) 2001 American Journal of Hypertension, Ltd.