Essential hypertension is one of the most common multi- factorial diseases, affecting 20%--30% of the human popula- tion （Ibrahim and Damasceno, 2012）. Based on the results of twin studies, adoption studies and statistical analyses of blood pressure （BP） across various pedigrees, it has been estimated that 30%--50% of the variability in blood pressure among the general population is genetically determined （Garcia et al., 2003）. Although the genetic mechanisms of essential hyper- tension have not been studied well, investigations for the genes that constitute the renin-angiotensin system （RAS） appear to be particularly promising, since this system plays a central role in the regulation of blood pressure （Ferrario, 2010）.
The association of polymorphisms in exon 1 of the WNK1 gene with essential hypertension in the minority groups of Hani and Yi of China was investigated in the case-control study.The sequence of 1257 bp containing the WNK1 gene exon 1 was determined in 1307 individuals（649 essential hypertension subjects and 658 controls）to identify SNPs in Hani and Yi minority groups.Four of eleven previously known SNPs （rs3168640,rs11885,rs11554421 and rs34880640）were identified.The SNP analysis indicated that SNPs rs11885 and rs11554421 were significantly associated with hypertension in both Hani and Yi populations,and rs34880640 was significantly associated with hypertension in Hani but not in Yi population,adjusted for covariates.Haplotype analysis indicated that the haplotype H1 significantly decreased the risk of hypertension in both populations.These results suggested that WNK1 polymorphisms were involved in the predisposition of essential hypertension in Hani and Yi populations and its effects showed a clear population specificity.This finding supported the importance of population specificity in determining the genetic factors associated with diseases and thus disease treatment.
