Heterogeneity of vitamin D receptor gene association with celiac disease and type 1 diabetes mellitus

Objective: Vitamin D has been shown to exert multiple immunomodulatory effects and is known to suppress T-cell activation by binding to the vitamin D receptor (VDR). To determine whether VDR gene polymorphisms are related to the susceptibility to celiac disease, we investigated its implication as a candidate gene in the Basque population. Because celiac disease and type 1 diabetes share common susceptibility loci, we also analyzed families with type 1 diabetes mellitus.Methods: A total of 37 families with celiac disease and 64 type 1 diabetic families of Basque origin with at least one affected offspring were genotyped for four VDR restriction-site polymorphisms (Fok I, Bsm I, Apa I and Taq I). The AFBAC approach was used to test for association.Results: Comparison of VDR genotypes of the patients with those of 88 healthy individuals identified “ff” as a risk genotype for celiac disease [p = 0.01; OR = 3.45 (1.12–10.79)]. On the other hand, a significantly higher frequency of haplotype “fBAt” was observed...