ABSTRACT
<p><b>OBJECTIVE</b>To determine whether vitamin D receptor(VDR) gene start codon polymorphisms and 3'-end region polymorphisms exerted a combined influence on bone mineral density(BMD) in Han postmenopausal women in Beijing area.</p><p><b>METHODS</b>The VDR Fok I and 3'-end region genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism in 110 unrelated postmenopausal women. BMD was measured at the lumbar spine (L(2-4)), femoral neck(Neck), Ward's triangle(Ward's) and trochanter (Troch) using duel-energy X-ray absorptiometry.</p><p><b>RESULTS</b>The frequencies distribution of Fok I, Apa I, Bsm I and Taq I alleles in this cohort all followed the Hardy-Weinberg equilibrium. No significant association of Fok I, Apa I or Taq I genotype with BMD in postmenopausal women was found when these polymorphisms were considered independently, except for Bsm I genotype. When a combined analysis of VDR gene Fok I and 3'-end region polymorphisms was carried out, cross-genotyping Fok I and Apa I polymorphisms was significantly associated with BMD at the L(2-4) (P<0.001), and cross-genotype of Fok I and Taq I was also significantly associated with BMD at the Neck and Troch sites (P<0.05). However, cross-genotyping Fok I and Bsm I polymorphisms was not significantly associated with BMD. Cross-genotyping Apa I and Bsm I or Taq I polymorphisms was not associated with BMD in postmenopausal women, either.</p><p><b>CONCLUSION</b>Although Fok I polymorphisms of VDR gene were not significantly associated with BMD in postmenopausal women, VDR gene Fok I and 3'-region polymorphisms (Apa I and Taq I) had a combined effect on the BMD in postmenopausal women.</p>