OBJECTIVETo investigate whether the WNK lysine deficient protein kinase 4 (WNK4) gene C1155547T polymorphism is associated with essential hypertension (EH) in Xinjiang Kazakhs and to assess the effect of the interaction between this polymorphism and environment factors on EH.

METHODSThe study covered 556 hypertension patients and 341 normotensive controls. The C1155547T was determined by Taqman probe real-time PCR method. Some biochemical index such as glucose, triglyceride and total cholesterol were also measured. All of these results were analyzed with Logistic regression analysis. Additive model was applied to assess the effect of interaction between the WNK4 gene C1155547T polymorphism and environment factors on hypertension.

RESULTSThe C1155547T polymorphism was consistent with Hardy-Weinberg equilibrium in both the case and control groups. There was significant difference in the genotype frequencies (P=0.003). The T allele frequency was significantly higher in the patient group (P=0.002). Logistic regression analysis revealed that the age, body mass index (BMI), total cholesterol as well as the CT+TT genotype frequency conferred increased risks for EH. Positive interaction between the C1155547T polymorphism and gender, BMI, glucose was observed. The ORs were 3.85 (95%CI:1.23-12.04), 5.91 (95%CI:1.99-17.57) and 8.77 (95%CI:1.04-73.93), respectively.

CONCLUSIONThe result suggested that the exon 7 C1155547T polymorphism in WNK4 gene might be associated with EH in Xinjiang Kazakhs, the T allele might be the risk factor of essential hypertension. There were interactive effects between the WNK4 gene C1155547T polymorphism and gender, BMI and glucose.