Background Recent published studies described correlations between endothelial nitric oxide synthase (eNOS) gene polymorphism and nephrotic syndrome (NS). Currently is accepted that the aetiology of NS is vast, unclear and variable in different parts of the world. There are few studies witch investigate the eNOS gene polymorphism in children. The aim of our study was to investigate three polymorphism of eNOS gene, namely C784T (rs2070744), eNOS G894T (rs1799983) and e NOS intron 4a/b in young NS patients.

Material and methods This case-control study was approved by the Ethical Committee from the University of Medicine and Pharmacy from TîrguMureş. A number of 232 children were included, 68 with NS and 164 healthy children. The DNA was extracted from peripheral fresh blood and amplified by polymerase chain reaction (PCR) using the restriction fragment length polymorphism (RFLP) method.

Results In the patients group we found the following genotypes: for e NOS T786C1: none CC, 53 CT and 14 TT; for eNOS G894T8: none TT, 32 GT and 28 GG; for eNOS 4a/4b: 28 4b/4b, 31 4a/4b and 9 4a/4a respectively. In the control group for eNOS T786C 1 control had the CC genotype, 128 CT and 35 TT. In the same group for eNOS G894T we found 17 TT, 55 GT, 92 GG genotype while for eNOS 4a/4b 122 were 4b/4b, 38 4a/4b and 4 4a/4a. We compared the genotypes and allele distribution for each polymorphism between studied groups but significant differences were observed only for e NOS 4a/4b polymorphism (p<0.0001, OR:3.45, CI95%: 2.16–5.51) and eNOS G894T (p=0.04, OR:1.91, CI95%: 1.04–3.5). The distribution of the combined variant genotypes and combined variant alleles of eNOS 4a and eNOS 894 G are significant different between the two groups (p<0.05). No statistically significant results were found after the evaluation of the combined variant genotypes/alleles for all investigated polymorphisms between evaluated groups (p>0.05).

Conclusion According to our results the polymorphisms of eNOS 4a/4b and eNOS G894T and the combined variant genotype/allele of them represent a risk factor for NS development.