Genetics of osteoporosis

Osteoporosis is a disease affecting mainly women but also an increasing num ber of men. The destruction of the bone microarchitecture and the reduction of bone mass lead to increased fragility and pathologic bone fractures. Fa mily studies and twin studies have shown that peak bone mass, mechanical st rength, and physiological bone turnover are subject to genetic control. Vit amin D receptor polymorphisms were one of the first genetic factors suggest ed to influence bone phenotype, although their impact on bone metabolism wa s initially overestimated. Meanwhile, polymorphisms in numerous other genes such as collagen I alpha1, estrogen receptor, transforming growth factor beta (TGF-beta), interleukin -1, interleukin-6, calcitonin,parathyroid hormone, and apolipoprotein E hav e been found to be associated with bone mineral density. In the interpretat ion of genetic findings, genetic differences between different ethnic group s, environmental factors such as calcium intake,vitamin D status, hormonal status, body size, and total body bone mineral density have to be considere d. Understanding the molecular physiology of the genes described in this ar ticle and all genes influencing bone metabolism identified in the future wi ll enable us to identify persons at risk for osteoporosis and to develop mo re specific therapies.