Association between Vitamin D Receptor Gene Polymorphism and NephrolithiasisRuggiero M.a · Pacini S.a · Amato M.b · Aterini S.b · Chiarugi V.a
aInstitute of General Pathology, University of Florence, and bKidney Stone Prevention Centre, Department of Nephrology and Urology, Misericordia e Dolce Hospital, Prato, Italy
Aims: To study the distribution of vitamin D receptor (VDR) gene alleles in hypercalciuric and nonhypercalciuric nephrolithiasis patients, hypothesizing that distinct biochemical parameters would be associated with different VDR genotypes. Methods: 12 hypercalciuric, 15 normocalciuric nephrolithiasis patients, and 150 healthy subjects were recruited. The individual genetic pattern for VDR was evaluated by DNA extraction followed by polymerase chain reaction amplification of the VDR gene and digestion with the restriction enzyme BsmI. Results: In the hypercalciuric group, Bb patients represented 50% (6/12); bb patients 33% (4/12), and BB cases were 16% (2/12). The VDR frequency distribution was not statistically different in hypercalciuric patients and controls (Bb 72%; bb 16%; BB 12%). In the nonhypercalciuric group, the prevalence of the bb genotype (7/15; 47%) was thrice the percentage of control subjects, while the percentage of BB patients was similar to that of the control group (2/15; 13%). Patients with the bb haplotype exhibited a higher daily urinary calcium excretion. Among hypercalciuric patients, after a calcium-restricted diet, bb patients showed a 39% reduction in daily urinary calcium excretion in comparison with a nonsignificant 13% reduction observed in BB subjects (p = 0.004). Conclusions: The effects of VDR gene polymorphism on calcium metabolism contribute to the understanding of the pathogenesis of urinary calculi.
Prof. Marco Ruggiero
Istituto di Patologia Generale
Viale Morgagni 50
I–50134 Firenze (Italy)
Tel. +39 055 411131, Fax +39 055 416908, E‐Mail AK.47@PRATONEXT.IT
Number of Print Pages : 6
Number of Figures : 1, Number of Tables : 4, Number of References : 21
Mineral and Electrolyte Metabolism
Vol. 25, No. 3, Year 1999 (Cover Date: May-June 1999)
Journal Editor: Shaul G. Massry, Los Angeles, Calif.
ISSN: 0378–0392 (print), 1423–016X (Online)
For additional information: http://www.karger.com/journals/mem