Association of eNOS gene intron 4 a/b VNTR polymorphisms in children with nephrotic syndrome

• The prevalence of the aa and ab genotypes or a alleles is not different between patients and controls.
• There is no association between eNOS4 polymorphisms and relapse frequency in SSNS.
• There is no association between eNOS4 genotypes and steroid response in NS.

To investigate the association of endothelial nitric oxide synthase gene intron 4 (eNOS4) polymorphisms with nephrotic syndrome, the eNOS4 genotypes were assessed in 161 children with nephrotic syndrome in comparison with 78 healthy subjects. We classified the children with nephritic syndrome into 2 groups: as steroid-sensitive nephrotic syndrome (SSNS) (n = 125) and steroid-resistant nephrotic syndrome (SRNS) (n = 36). The eNOS4 polymorphisms were analyzed by polymerase chain reaction. The frequencies of eNOS4 aa, ab and bb genotypes were 3%, 31%, and 66% in all the nephrotic syndrome groups, and 1%, 23%, and 76% in the control group (x2 = 2.87, p > 0.05). In addition, the frequencies of eNOS4 aa, ab and bb genotypes were 2%, 33%, and 65% in SSNS group, and 5%, 28%, and 67% in the SRNS group (x2 = 1.13, p = 0.567). The present study is the first to investigate eNOS4 gene polymorphisms in children with SSNS and SRNS. Our data show that the eNOS4 gene polymorphisms were not associated with the development, frequent relapse and response to steroid in nephritic syndrome.