One thousand unrelated postmenopausal women of Mexican-Mestizo ethnic origin, who attended the outpatient clinic for routine, general medical evaluation, were invited and 750 women accepted to participate in the study. A structured questionnaire for risk factors was applied and BMD was measured in total hip and lumbar spine by dual-energy X-ray absorptiometry. DNA was obtained from blood leukocytes. Three single-nucleotide polymorphisms in TNFRSF11B gene were studied: rs4355801, rs2073618, and rs6993813. Real-time PCR allelic discrimination was used for genotyping. Deviations from Hardy-Weinberg equilibrium were tested. Pairwise linkage disequilibrium between single nucleotide polymorphisms was calculated by direct correlation r2, and haplotype analysis was conducted.
Of the subjects, 31 % had osteoporosis, 45.1 % had osteopenia, and 23.9 % had normal BMD. Genotype and allele distributions showed no significant differences; however, A-G-T haplotype was associated with variations in femoral neck BMD (P = 0.022).
In our study population, analysis of the haplotypes of TNFRSF11B is a better genetic marker for variations in BMD.