Polymorphisms in the vitamin D receptor gene and the risk of calcium nephrolithiasis in children

Objective: Polymorphism in the Vitamin D Receptor (VDR) gene has recently been reported to be associated with calcium metabolism disorders. This study was conducted to investigate the association of VDR gene polymorphism with the risk of calcium nephrolithiasis. Methods: We investigated the VDR ApaI, BsmI and TaqI polymorphisms, in relation to serum calcium, phosphate, intact parathyroid hormone and 1.25(OH)(2)D-3 in 64 hypercalciuric stone-forming children and 90 healthy children. DNA was isolated from peripheral blood, and genotyping was performed with PCR-based methods. Results: The frequency of ApaI AA genotype was significantly higher in the children with calcium nephrolithials than the controls (x(2) = 9.5; p = 0.008). The distribution of Bsml and TaqI genotypes in stone-forming patients was similar to those in the control group. There was a significant association between TaqI TT genotype and the strength of the family history. The patients with TT genotype were observed to have a 8 times more risk than patients with Tt/tt genotype for recurrent stone episodes (OR 8, 95%CI 1.61-39.6). Conclusion: VDR genotype determination may provide a tool to identify individuals who are at a risk for calcium nephrolithiasis. (C) 2003 Elsevier Science B.V. All rights reserved.