[The 869C>T And 915G>C Polymorphisms of TGF-ß1 and Type 1 Diabetic Retinopathy in the Algerian Population]. / Polymorphismes 869C> T et 915 G>C du TGF-ß1 dans la rétinopathie du diabète de type 1 chez la population algérienne.

INTRODUCTION: Diabetic retinopathy (DR) is characterized by chronic low-grade inflammation in which the effects of genetic factors is well established. The objective of our study is to explore an association of the 869C>T and 915G>C polymorphisms of the TGF-ß1 gene with type 1 diabetic retinopathy in the Algerian population. PATIENTS AND METHODS: A case-control study was carried out in which the SNPs 869C>T and 915G>C of the TGF-ß1 gene were analysed by the PCR-SSP technique. We compared the distribution of allelic and genotypic frequencies between patients with and without retinopathy and looked for an association between these polymorphisms and certain clinical characteristics of and risk factors for diabetic retinopathy. RESULTS: A significant increase in the frequencies of the C allele (P=0.03) and GG genotype (P=0.007) of the 915 G>C polymorphism were found, respectively, in patients without and with retinopathy. However, no significant difference was found for allelic and genotypic frequencies of the 869C>T SNP (all P>0.05) or associations between genotypes and clinical characteristics or risk factors for DR. CONCLUSION: Our preliminary results suggest that the C allele of the 915 G>C polymorphism of TGF-ß1 is protective against type 1 diabetic retinopathy in the Algerian population, while the GG genotype could confer susceptibility to it.

[T-786C endothelial nitric oxide gene polymorphism and type 1 diabetic retinopathy in the Algerian population]. / Polymorphisme T-786C de l'eNOS dans la rétinopathie du diabète de type 1 chez la population algérienne.

INTRODUCTION: Diabetic retinopathy (DR) results from interactions between genetic and environmental factors. We were interested in the endothelial nitric oxide gene (eNOS), given the involvement of this enzyme in functional alterations in the retinal microvasculature in diabetes. The goal of our study was to assess the association of T-786C endothelial nitric oxide synthase (eNOS) gene polymorphism with diabetic retinopathy in the Algerian population. PATIENTS AND METHODS: Our study enrolled 110 patients with and without DR. All subjects were genotyped for the T786C eNOS polymorphism using the PCR-RFLP method. We also investigated the association between this polymorphism and certain clinical and laboratory characteristics of patients with DR. RESULTS: A significant increase in the frequency of the CC genotype is noted in subjects without DR (P=0.03). We also report a significant increase in the frequencies of the TT+TC genotypes in individuals with DR (P=0.03). However, the association between the different genotypes and clinical or laboratory profiles in patients with DR reveals that the NO level is lower in subjects carrying the TT genotype (P=0.039). CONCLUSION: Our preliminary results suggest that the CC genotype could confer protection from type 1 diabetic retinopathy in the Algerian population, while the T allele seems to confer susceptibility.