In this case-control study, the relationship of the -786T/C, the VNTR intron 4 a/b and the 894G/T (Glu298Asp) polymorphisms in the eNOS gene with the presence or severity of diabetic retinopathy was analyzed in 630 Caucasian-Brazilians with type 2 diabetes (434 with and 196 without diabetic retinopathy).
In both the cohorts, consistently lower prevalence and decreased risk of DR was observed in patients with ba, aa and ba + aa genotype of 27VNTR (a/b), C-a-G and C-a-T haplotype (allele of T-786C, 27VNTR a/b and G894T) carrying "C" allele of T-786C and "a" allele of 27VNTR (a/b).
Lower prevalence of mutant 4a (P = 0.011), and heterozygous 4b/4a (P = 0.042) were seen in the DR compared to the DWR groups; the allele and genotype distribution of the Glu298Asp and T-786C polymorphisms were comparable between DR and DWR groups.
We studied three eNOS genetic polymorphisms: a single nucleotide polymorphism in the promoter region (T(-786)C), in exon 7 (Glu298Asp), and a variable number of tandem repeats in intron 4 (b/a) in 103 healthy controls, and in 170 patients with T2DM (without DR, N=114; with DR, N=56).