Coding region analysis of vitamin D receptor gene and its association with active calcium stone disease.

The purpose of this study was to evaluate the impact of vitamin D receptor (VDR) gene polymorphisms on the status of active renal calcium stone formation. Male active renal calcium stone formers (ASF, final N = 106) with two episodes of stone relapse in the past 5 years were enrolled from December 2008 to April 2009. Controls (N = 109) were selected from age range- and gender-matched individuals who had no evidence or history of stone disease. Sequencing and single-strand conformational polymorphism were used to determine VDR polymorphisms in the patients and controls. Three polymorphisms were identified in the VDR gene: (1) start codon polymorphism (rs2228570T>C; p.M1T); (2) C/T polymorphism in the second intron (NT-029419.12: g.10416049C>T); (3) a silent polymorphism in exon 9 (rs731236T>C; p.I352I). Start codon polymorphism was the only one that was associated with the status of calcium stone formation (p < 0.05). We performed a complete coding genome analysis of VDR gene and observed that only start codon polymorphism was related to the status of active calcium stone formation.