The study of CTLA‐4 and vitamin D receptor polymorphisms in the Romanian type 1 diabetes population

AbstractSeveral studies suggested that part of the genetic susceptibility for Type 1 diabetes (TIDM) is encoded by some polymorphisms of CTLA‐4 gene (2q33) and of Vitamin D Receptor gene (VDR; 12q12‐14). Our aim was to assess their contribution to TIDM genetic susceptibility in the Romanian population. We typed CTLA‐4 49 A/G and VDR FokI (F/f), ApaI (A/a) and TaqI (T/t) polymorphisms by Sequence Specific Primer PCR (SSP‐PCR) in 204 Romanian diabetic families (756 individuals: 212 TIDM probands and 544 unaffected parents and siblings). We studied alleles transmission using the Transmission Disequilibrium Test (TDT). We found an increased transmission of CTLA‐4 49G allele to diabetics (54.8%, p=0.11). The transmission of F (56.1%, p=0.063), a (55.7%, p=0.061) and T (51.8%, p=0.37) alleles of VDR gene to diabetics was increased but did not reach statistical significance. In conclusion we found the same increased transmission of CTLA‐4 49 G allele to diabetics as previously reported. VDR FoqI F allele seems to be predisposing while TaqI T allele seems to be protective.