Association of the C-344T polymorphism of CYP11B2 gene with essential hypertension in Hani and Yi minorities of China Wenru Tang, Hongyan Wu, Xuhong Zhou, Baowen Cheng, Yongli Dong, Li He, Haijing Yu, Lin Xu, Jing Lu, Kaiyuan Li, Chunjie Xiao * Laboratory for Conservation and Utilization of Bio-resources and Human Genetics Center of Yunnan University, #2 N. Cuihu Rd. Kunming, Yunnan 650091, PR China Received 3 March 2005; received in revised form 6 July 2005; accepted 6 July 2005 Available online 26 August 2005 Abstract Background: Aldosterone synthase (CYP11B2) is a key enzyme in the biosynthesis of aldosterone. Recently, a C-344T polymorphism in the promoter region of the CYP11B2 gene has been reported to be in association with high blood pressure. We investigated the association between this polymorphism and essential hypertension in Hani (n =305 individuals) and Yi (n = 233 individuals) minorities of China. Methods: CYP11B2 genotyping with polymerase chain reaction –restriction fragment length polymorphism was performed in 267 normotensive subjects and 271 essential hypertensive subjects. At the same time, the T(-344)C polymorphism detection in 33 subjects was also performed by sequencing. Result: The frequency of CYP11B2 C-344T genotype in normotensive controls and essential hypertensive cohort in Hani population were TT: 0.729 vs. 0.610; CT + CC: 0.271 vs. 0.390, respectively. The frequency of CYP11B2 C-344T genotype in normotensive controls and essential hypertensive cohort in Yi population were TT: 0.612 vs. 0.475; CT + CC: 0.388 vs. 0.525, respectively. The frequency of CC + CT genotype in the essential hypertensive group was significantly higher than that in the normotensive controls in both Hani and Yi populations ( P < 0.05). Conclusion: The -344C allele of the CYP11B2 may play a role in genetic predisposition to developing essential hypertension in Hani and Yi minorities of China. D 2005 Elsevier B.V. All rights reserved. Keywords: Essential hypertension; Polymorphism; Aldosterone synthase; Hani minority; Yi minority 1. Introduction Essential hypertension is a multifactional disorder that is influenced by genetic and environmental factors [1]. Genes of the rennin-agiotensin-aldosterone system (RAAS), including angiotensinogen (AGT), angiotensin I-converting enzyme (ACE), type I angiotensin (Ang) II receptor (AT1R) and CYP11B2, are natural candidates for sodium homeo- stasis and blood pressure regulation. Polymorphisms of these genes have been major targets for molecular analyses in association with hypertension. Polymorphisms such as AGT M235T, ACE I/D, and AT1R A1166C have been investigated in association studies with hypertension [2–5]. Aldosterone synthase, a mitochondrial P450 oxidase, has steroid 11h-hydroxylase activity as well as the 18-hydrox- ylase and 18-oxidase activities required for the terminal steps of aldosterone biosynthesis. Expression of this enzyme is limited to the adrenal zona glomerulosa, where it is principally regulated by serum levels of potassium and angiotensin II [6,7]. CYP11B2 gene encoding aldosterone synthase was mapped to chromosome 8q24.3 [8]. To date, 3 common polymorphic variants of CYP11B2, C-344T at promoter region, a mutation in intron 2, and K173R in 0009-8981/$ - see front matter D 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.cccn.2005.07.006 Abbreviations: CYP11B2, Aldosterone synthase; RAAS, rennin-agio- tensin-aldosterone system; AGT, angiotensinogen; ACE, angiotensin I- converting enzyme; Ang, angiotensin; AT1R, type I angiotensin II receptor; SBP, systolic blood pressure; DBP, diastolic blood pressure; BP, blood pressure; BMI, body mass index; NH, normotensive; EH, essential hypertensive; SF-1, steroidogenic transcription factor. * Corresponding author. Tel.: +86 871 5034636; fax: +86 871 5034636. E-mail address: cjxiao@public.km.yn.cn (C. Xiao). Clinica Chimica Acta 364 (2006) 222 – 225 www.elsevier.com/locate/clinchim