Vitamin D Receptor Gene Polymorphisms and Autoimmune Thyroiditis: Are They Associated with Disease Occurrence and Its Features?

PURPOSE

Vitamin D, besides its role in calcium-phosphorus metabolism, turned out to play a significant immunomodulating function. Until now four single nucleotide polymorphisms of vitamin D receptor gene (), rs2228570 (I), rs1544410 (I), rs7975232 (I), and rs731236 (I), have been studied in autoimmune thyroid disorders, with conflicting results. Another functional polymorphism of the gene, rs11568820 (Cdx2), has been shown to influence the immune system, although it has not been studied for its association with autoimmune thyroiditis to date. Therefore, the study aimed to evaluate the association of these five gene polymorphisms with susceptibility to autoimmune thyroiditis among Caucasian Polish population. A relationship between the studied polymorphisms and selected clinical features of the disease was additionally assessed.

METHODS

223 patients with autoimmune thyroiditis and 130 control subjects were enrolled in the study. polymorphisms were studied by PCR-RFLP or TaqMan real-time PCR.

RESULTS

Allele and genotype distributions of any of the studied polymorphisms did not differ significantly between patients and controls. Similarly, frequencies of haplotypes derived from rs1544410-rs7975232-rs731236 (I-I-I) polymorphisms were not significantly different in the two studied groups. However, a weak association between rs1544410 (I) or rs7975232 (I) polymorphisms and thyroid volume was found (p = 0.03 and p = 0.04, resp.).

CONCLUSIONS

Our results suggest that gene is not a major susceptibility factor for autoimmune thyroiditis development, at least in Caucasian Polish population.