Fas, Fas Ligand, and Vitamin D Receptor FokI Gene Polymorphisms in Patients with Type 1 Diabetes Mellitus in the Aegean Region of Turkey

Objective: Several gene polymorphisms have been reported to be associated with the risk of developing type 1 diabetes. Among them, the human leukocyte antigen locus is the strongest genetic determinant. To identify additional genetic markers, we aimed to evaluate the relationship between the Fas, Fas ligand (FasL), and vitamin D receptor (VDR) FokI gene polymorphisms and the susceptibility to type 1 diabetes in the Aegean region of Turkey. Materials and Methods: Eighty-five patients with type 1 diabetes and 80 healthy controls were included in this study. The Fas -670A/G, FasL -843C/T, and VDR FokI gene polymorphisms were evaluated using the polymerase chain reaction-restriction fragment length polymorphism method. Results: The evaluation of the Fas genotype and the gene allele frequency did not show statistically significant differences between the patient and control group. Distribution of the FasL genotype differed significantly between patients and controls. The distribution of the VDR FokI genotype and allele frequencies differed significantly between the patients and controls. Individuals with type 1 diabetes presented less commonly with the FokI f allele. Conclusions: Our findings suggest that the FasL -843C/T and VDR FokI gene polymorphisms are associated with type 1 diabetes in the Agean region of Turkey; however, the Fas -670A/G gene polymorphism is not.