[Association of vitamin D receptor gene polymorphisms with idiopathic hypoparathyroidism phenotypes]

Objective: To explore the association of vitamin D receptor (VDR) gene polymorphisms with idiopathic hypoparathyroidism (IHP). Methods: Two hundred and three patients with IHP and 209 healthy age- and sex-matched subjects were recruited at Peking Union Medical College Hospital between December 1987 and December 2015 as case group and control group, respectively. The VDR gene polymorphisms including rs739837, rs3847987 and rs2228570 were analyzed by Sequenom Mass Array. The frequency of different genotypes and alleles was detected, then their association with pathogenesis of IHP was analyzed. The clinical characteristics, biochemical indicators were collected to explore the genotype-phenotype relationship. The role of reactions to vitamin D treatment were compared between patients with different genotypes. Results: There was no significant difference in the genotypes and allele frequency distribution of SNPs between the two groups (all P>0.05). However, in the initially-treated patients, the genotypes of rs739837 were related to serum calcium level (r=0.186, P=0.026). And patients with GG genotype of rs2228750 had higher level of urine calcium than GA and AA (277.7 mg vs 141.1 mg, P=0.024) after treating with oral vitamin D(3) and calcium. Conclusions: Functional SNPs of VDR gene including rs739837, rs3847987 and rs2228570 might be irrelevant to the pathogenesis of IHP. But the genotypes of rs739837 were related to serum calcium level, and rs2228570 may have an effect on the different responses to vitamin D and its analogues in IHP patients.