Objective: To examine the association between insertion/deletion polymorphism in intron 4 of ecNOS gene (ecNOS 4 b/a) and end-stage chronic renal failure (ESCRF) in Han people in Tianjin, China.
Methods: The genotypes of ecNOS 4 b/a polymorphism were detected by PCR-minisatellite DNA detection technique. 67 CRF patients on hemodialysis were included in the study group, with 70 healthy volunteers as controls.
Results: (1) The genotype frequencies were 79.1%, 19.4% and 1.5% in the patients and 91.4%, 8.6% and 0% in the controls for bb, ba and aa genotypes, respectively. (2) The allele frequencies were significantly different between the patients and controls (chi(2) = 4.617, P < 0.05). The a/(a + b) odds ratio (OR, 95% confidence interval) of the patients vs controls was 2.64 (1.09, 6.43) (Z = 2.14, P < 0.05). (3) The average age of the patients with allele a was 47.43 +/- 11.63, while that without allele a was 58.08 +/- 13.68. The difference was significant, t = 2.664 (P < 0.01). (4) The frequency of allele a is lower in Han people of Tianjin (4.3%) than that in Japanese (10.1%) (chi(2) = 4.898, P = 0.027).
Conclusions: (1) The frequency of allele a is lower in Han people of Tianjin than that in Japanese and Westeners; (2) ecNOS 4 b/a polymorphism is associated with ESCRF in Han population of Tianjin and allele a is associated with the increased risk of ESCRF.