LACK OF ASSOCIATION BETWEEN VITAMIN-D-RECEPTOR GENOTYPES AND OSTEOPOROSIS IN KOREANS

To evaluate whether common allelic variants in the gene encoding the v itamin D receptor (VDR) were useful in predicting differences in bone mineral density (BMD) and bone turnover rate in Koreans, we analyzed t he restriction pattern of the polymerase chain reaction product of the VDR gene with the Bsm1 enzyme and serum osteocalcin in patients with osteoporosis. The prevalence of the BE genotype in the controls was ex tremely low when compared with that in other reports: the BE, Bb, and bb genotypes accounted for 1.4%, 12.9%, and 85.7%, respectively. Only 2.8% of those patients with osteoporosis had the BE genotype. In contr ast, 12.5% had the Bb genotype, and 84.7% had the bb genotype. The pre valence of the BE genotype in patients with severe osteoporosis was al so extremely low: the BE, Bb, and bb genotypes accounted for 0%, 12.4% , and 87.6%, respectively. Compared with the mean serum osteocalcin le vel of the pre- and postmenopausal controls, the level in patients wit h severe osteoporosis was higher, and this was statistically significa nt. As expected, a negative correlation was observed between the serum osteocalcin levels and the age-matched Z scores for spinal BMD. Howev er, no correlation was found in the femoral neck BMD. These results su ggest that restriction fragment length polymorphism analysis of the VD R gene with a Bsm1 restriction enzyme in Koreans is not helpful for ea rly detection of patients at risk of developing osteoporosis. This is true even in patients with a high rate of bone turnover. Our data sugg est extreme ethnic differences in the pattern of prevalence of the VDR allele.