title: Polymorphisms in the vitamin D receptor and the androgen receptor gene associated with the risk of urolithiasis.
abstract: Transcriptional activity of the vitamin D receptor (VDR) gene is regulated by androgen receptor (AR) gene and both are associated with renal stone formation. We examined gene polymorphisms of VDR (PCR-RFLP) and AR (GeneScan analysis) in 125 stone formers and 150 controls from north India. Genotype Ff of Fok-I and Tt of Taq-I demonstrated significantly higher risk (P<0.001, OR=3.559 and P=0.019, 1.830 respectively). Variant f allele exhibited 1.7-folds higher risk. Ff of Fok-I and Aa of Apa-I gene polymorphism showed higher risk in males only. Mean CAG repeat was significantly higher in hypercalciuric patients as compared to normocalciuric (mean=21.62 ± 3.384 vs. 20.11 ± 3.182; P=0.034). Combined effects 1.8-folds higher risk in patients with Tt genotype of Taq-I and short CAG repeat. Thus, association of FokI and TaqI VDR gene polymorphisms suggest VDR as an important genetic marker for urolithiasis. Further, patients with combination of Tt of Taq-I and short CAG repeat were at higher risk for stone formation.
authors.affiliation: Department of Urology and Renal Transplantation, Sanjay Gandhi Post Graduate Institute of Medical Sciences (SGPGIMS), Raebareli Road, Lucknow, 226014 Uttar Pradesh India  ; Department of Urology, SGPGIMS, Raebareli Road, Lucknow, 226014 India.
authors.forename: Rama Devi
authors.initials: RD
authors.lastname: Mittal
authors.forename: D K
authors.initials: DK
authors.lastname: Mishra
authors.forename: P
authors.initials: P
authors.lastname: Srivastava
authors.forename: P
authors.initials: P
authors.lastname: Manchanda
authors.forename: H K
authors.initials: HK
authors.lastname: Bid
authors.forename: R
authors.initials: R
authors.lastname: Kapoor
keywords: Androgen receptor; Polymorphism; Urolithiasis; Vitamin D receptor