ASSOCIATION ANALYSIS OF CA REPEAT POLYMORPHISM OF THE ENDOTHELIAL NITRIC-OXIDE SYNTHASE GENE WITH ESSENTIAL-HYPERTENSION IN JAPANESE

The nitric oxide synthase (NOS) gene is thought to be associated with essential hypertension (EH), because NO is implicated in endothelium-m ediated vasodilation. We investigated the possible association between the alleles of simple tandem repeat DNA polymorphism of the endotheli al constitutive NOS (cNOS) gene and EH in Japanese subjects. In all, 1 00 patients with EH and 123 subjects with normal blood pressure were s tudied. Polymerase chain reaction was used to amplify the CA repeat si te in the endothelial cNOS gene and alleles based on the CA repeat num ber were determined. The allele frequencies in the hypertensive group and normotensive group were then compared. Twenty-three alleles were i dentified in this study of Japanese subjects. The overall distribution s of allele frequencies in the two groups were not significantly diffe rent. However, comparing the allele frequencies in the EH group withou t left ventricular hypertrophy (LVH) and the normotensive group, the o verall distributions were significantly different (p=0.019). The 33-re peat allele was found more frequently in the EH group without LVH than in the normotensive group (p=0.000047, Odds ratio=3.71). In conclusio n, the 33-repeat allele of the endothelial cNOS gene is associated wit h EH without LVH, and may be a genetic marker of EH in Japanese subjec ts.