Genetic studies of osteoporosis

Osteoporosis is a common condition of men and women, which is characterised by an increase in bone fragility due to a reduction in the amount of bone tissue. Predisposition to osteoporosis is largely genetically determined, and it is likely that several genes, each having a small effect, are involved. Bone density is determined by the peak bone mass achieved, and the rate and timing of subsequent bone loss. Twin and family studies suggest that the genetic determinants of bone density in later life influence predominantly, but not exclusively, peak bone mass. Although many genes influence bone density in both males and females, at different skeletal sites and in different age groups, it is likely that the magnitude of individual genetic effects differs in different population subsets and in different environmental settings. Thus, weak to moderate genetic effects might be identified only in specific subsets of the population. Rapid advances in the field of human genetics during the past decade have greatly improved our chances of successfully identifying genes that are involved in complex genetic conditions such as osteoporosis, and ultimately might lead to the development of new diagnostic and predictive tests as well as novel treatments for this condition. In this review, we have outlined the methods that are currently being employed to identify osteoporosis genes and also the progress that has been made to date in this field.