The association of FokI and ApaI polymorphisms in vitamin D receptor gene with autoimmune thyroid diseases in the northwest of Iran

Some genetic factors are involved in the etiology of Hashimoto thyroiditis and Graves’ disease as autoimmune thyroid diseases (AITDs). Effects of vitamin D receptor gene polymorphisms in AITDs development have already been investigated in some previous studies. However, no study has been done on the association between VDR FokI and ApaI polymorphisms and AITDs in an Iranian population. In this study, the possible effects of FokI and ApaI polymorphisms on AITDs were investigated in the population of northwest of Iran.

A total of 121 AITDs adult patients and 117 healthy controls matched by age and sex in the same population were included in this study. FokI and ApaI polymorphisms were genotyped by polymerase chain reaction- restriction fragment length polymorphism (PCR-RFLP). Chi-square test and odds ratio (OR) with 95% CI were used to analyze the data.

FokI and ApaI genotypes frequencies were not significantly different between the 2 groups (p= 0.06, p= 0.73, respectively). However, FokI "CC" and "CT" genotypes were related to AITDs risk (p= 0.03; OR= 3.75; 95% CI, 1.16-12.17 and p= 0.04; OR= 3.41; 95% CI, 1.03-11.28, respectively).

These data suggest that FokI polymorphisms are involved in AITDs susceptibility in the population of northwest of Iran.