[Genetics and pharmacogenetics of osteoporosis]

Osteoporosis is a serious disease characterized by high morbidity and mortality due to atraumatic fractures. In pathogenesis of osteoporosis, except environment, internal factors, such as hormonal dysbalance and genetic background, are also in play. In this review, candidate genes for osteoporosis are classified according to metabolic or hormonal pathways, which regulate bone mineral density/and or quality (estrogen, RANKL/RANK/OPG, mevalonate, Wnt circuit, genes for collagen and vitamin D). Authors discuss the perspectives of practical utilization of pharmacogenetics (identification of single candidate genes using PCR) or pharmacogenomics (using genome wide association studies) in choice of optimal treatment of osteoporosis. Potentional predictors of effectivity of antiresorption therapy are genes ER, FDPS, Cyp19A1, VDR, Col1A1 and gene of Wnt pathway. Moreover, polymorphisms of CYP2C gene, but also FDPS may identify patients with high risk of undesirable effects of bisphosphonates (osteonecrosis of jaw). Unfortunately, results of the most association studies has not been confirmed by other investigators. The controversial results could be explained by different methodic approaches in individual studies (different sample size, homogenity of investigated groups, ethnic differences or linkage disquilibrium between genes). Key cliff of association studies is low variability (7-10 %) of bone phenotypes associated with investigated genes. Nevertheless, identification of new genes and verification their association with bone density and/or quality using both PCR and genome wide association studies remain to be a great challenge targeting optimal prevention and treatment of osteoporosis.