Biologie moléculaire : accès libre

Association of Vitamin D Receptor Gene Polymorphisms and Type1 Diabetes in an Egyptian Population

Abstract

Mona Gamal Elgazzaz

Aim and background: Vitamin D is known for its immune modulatory functions and its role in normal insulin secretion. Vitamin D acts via vitamin D receptor gene (VDR). The study was conducted to assess the relationship between Apa I and Taq I restriction site polymorphisms of vitamin D receptor gene and type1 diabetes in an Egyptian population.

Subjects and Methods: One hundred Egyptian participants (1-20 years old) of both sexes were recruited in this study. Fifty of them were type 1 diabetes patients and the other fifty were control non diabetic subjects. Apa I and Taq I variations were tested using Polymerase Chain Reaction and Restriction Fragment Length Polymorphism.

Results: Genetic analysis revealed that AA and Tt genotypes were predominant in the two study groups with higher frequency among patients group, whereas, aa and tt genotypes were predominant among controls (14% and 10%, respectively). Combined genotypes AATt, AAtt and aaTT were significantly more frequent in controls (P value of odds ratio 0.032, 0.033, 0.002, respectively). The haplotype AT was more frequent among diabetics (41%), whereas, haplotypes At and aT were more frequent in control group (39%, 29%, respectively). Linkage analysis of the two markers showed strong linkage disequilibrium between two markers (D’=1).

Conclusion: Apa I and Taq I VDR gene polymorphisms have an association with T1D and may predispose to the risk of T1D affection. While, genotypes AATt, AAtt and aaTT and haplotypes At and aT seem to have a possible protective effect against T1D.