ESR1 and osteoporosis: The genetic variability of Asian and Caucasian populations was observed at restriction sites exhibiting polymorphisms of five important candidate genes for BMD: CASR-BsaHI, alpha 2HS-glycoprotein (AHSG)-SacI, estrogen receptor alpha (ESR1)-PvuII and XbaI, vitamin D receptor (VDR)-ApaI and parathyroid hormone (PTH)-BstBI. The results of the statistical analysis between the two populations revealed a significant allelic and genotypic differentiation in polymorphisms associated with osteoporosis.