Vitamin D receptor (VDR) gene polymorphisms and age onset in type 1 diabetes mellitus

Vitamin D receptor is a mediator of immune responses through the action of vitamin D, which is capable of regulate the insulin secretion by the pancreas. Since polymorphisms in the vitamin D receptor (VDR) gene might modulate vitamin D function, and thus immunologic response, VDR is possibly able to influence the predisposition to type 1 diabetes mellitus (T1DM). The aim of this work was to perform an association study among VDR polymorphisms and T1DM susceptibility, as well as the correlation with the disease onset. Two hundred and four T1DM patients and 217 controls, from Northeast Brazil, were genotyped for five tagSNPs, covering the whole VDR gene. Our results indicated an association between rs1540339 and rs4760648 SNPs (p = 0.02 and p = 0.03, respectively) and T1DM. No association was found with T1DM onset and age at diagnose. To our knowledge, this is the first association study in T1DM where the whole VDR gene was analyzed, and our results indicate that VDR polymorphisms could be important for T1DM susceptibility, but do not seem to be associated to age at disease onset.