No association between alpha-adducin 460 polymorphism and essential hypertension in a Japanese population

Many unknown genetic factors are involved in the pathogenesis of hypertension. Recently, the reverse genetic approach revealed that some genetic variants, such as angiotensinogen, lipoprotein lipase, and alpha-adducin gene polymorphisms, increase the risk for hypertension. Both in rat and human, the genetic predisposition to hypertension was confirmed only for angiotensinogen and alpha-adducin genes. Adducin is a membrane cytoskeletal protein, which is thought to regulate sodium transport. Abnormalities of membrane sodium transport in the kidney play an important role in hypertension. A recent report by Cusi et al showed that the Trp allele of alpha-adducin polymorphism (Gly 460 Trp) is associated with an increased risk of hypertension in whites, which led us to carry out a case-control study to examine whether the same association is observed in the Japanese population. We recruited 170 hypertensive and 194 normotensive Japanese subjects and compared the genotype distribution of alpha-adducin 460 polymorphism between cases and controls and between whites and Japanese. Trp allele frequency of controls in the Japanese subjects was twice as high as in the whites. However, no association was observed between alpha-adducin polymorphism and hypertension. Furthermore, alpha-adducin 460 polymorphism was not associated with any clinical characteristics. Accordingly, we concluded that alpha-adducin 460 polymorphism is not a major genetic risk for hypertension in Japanese people.