Genetics of Osteoporosis

Genetic components are known to strongly influence bone mineral density (BMD) and bone architecture and turnover, playing an important role in determining risk of osteoporosis and fragility fractures. Twin and family linkage studies confirmed the importance of genetic factors in the individual variance of bone mass peak, BMD, bone geometry, and metabolism and, thus, in predisposition to osteoporosis and related fractures. Osteoporosis is a complex, multifactorial disorder whose pathogenesis is due to the addictive effects of various genetic determinants interacting with environmental influences and lifestyle habits. Several genes have been associated with bone mass and other determinants of fracture risk, each of them exerting a relatively modest single effect on the bone tissue. The synergic action of various predisposing alleles, within different genes, in association with environmental and lifestyle risk factors is presumably responsible for osteoporosis development and fragility fracture occurrence. This chapter aims to review the current knowledge on major genetic factors involved in the regulation of bone mass, architecture, and turnover, thus exerting a possible role also in the pathophysiology of osteoporosis.