Vitamin D receptor and calcium-sensing receptor gene polymorphisms in hypercalciuric stone-forming patients.
OBJECTIVE
Some studies have identified an association of kidney stone formation with vitamin D receptor (VDR) or calcium-sensing receptor (CaSR) polymorphisms. We aimed to evaluate the association between these polymorphisms with urinary calcium excretion (uCa) in calcium- stone-forming patients.


METHODS
VDR polymorphism, detected by BsmI digestion, and 3 CaSR polymorphisms (G/T at codon 986, G/A at codon 990 and C/G at codon 1011), detected by direct sequencing, were evaluated in 100 hypercalciuric (HCa) and 101 normocalciuric (NCa) calcium-stone-forming patients.


RESULTS
The total allelic frequency of VDR polymorphism was: 16% BB, 49% Bb and 35% bb. The prevalence of bb genotype was significantly higher in the HCa when compared to the NCa group (43 vs. 27%). With respect to CaSR polymorphisms, 986S, 990G and 1011E variant alleles were detected, respectively, in 5, 4 and 3% of the whole sample and 5 CaSR haplotypes were identified: 94% ARQ (wild-type), 3% SRQ, 1.5% AGQ, 1.0% ARE and 0.5% AGE. No statistical differences have been observed between NCa and HCa with respect to these CaSR haplotypes.


CONCLUSIONS
The present study suggested that bb homozygous for VDR polymorphism was overrepresented in hypercalciuric stone formers. Urinary calcium excretion was not associated with CaSR polymorphism in the present sample.
Ferreira
Larissa Gorayb
LG
Nephrology Division, Universidade Federal de São Paulo, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
Pereira
Alexandre Costa
AC
Heilberg
Ita Pfeferman
IP
D000328:Adult; D001938:Brazil / Q000453:epidemiology; D015897:Comorbidity; D005260:Female; D020022:Genetic Predisposition to Disease / Q000453:epidemiology / Q000235:genetics; D006801:Humans; D053565:Hypercalciuria / Q000453:epidemiology* / Q000235:genetics*; D007669:Kidney Calculi / Q000453:epidemiology* / Q000235:genetics*; D008297:Male; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D015995:Prevalence; D018167:Receptors, Calcitriol / Q000235:genetics*; D044169:Receptors, Calcium-Sensing / Q000235:genetics*; D018570:Risk Assessment; D012307:Risk Factors
D018167:Receptors, Calcitriol; D044169:Receptors, Calcium-Sensing