For the total population and for males, the C-C-C haplotype (established from T1880C, C602A and T1559C) was significantly higher among essential hypertension patients than among control individuals as well as in hypertensive males and normotensive males (P = 0.008 and 0.012). The C-A-T haplotype was higher in the EH group than in the NT group (P = 0.015) among males. There were no significant differences in other haplotypes between the EH and NT groups in males, females, or over the entire population.