Genetics of osteoporosis.

Osteoporosis is a systemic skeletal disease comprising rarefaction of bone structure and loss of bone mass, finally leading to increased fracture risk. As a part of its multifactorial aetiology, twin and family studies have demonstrated an important genetic component of osteoporosis regarding many parameters of bone properties e. g. bone mineral density, with a heredity of 60-80 %. Whole genome screens, linkage analysis and candidate gene research have contributed to our current knowledge about genetic loci in osteoporosis. Genotyping of collagen alpha I, lactose intolerance or estrogen receptor alpha alleles are under investigation for their importance in individual and epidemiological practice, e. g. the European Union "GENOMOS" project with more than 50,000 subjects. In future, improved genotyping methods and design strategies as well as large scale epidemiological studies in the general population will bring the genetics of complex diseases such as osteoporosis to a point of success comparable to where mendelian genetics now firmly resides. Given the potential of these new techniques, a paradigm shift may occur both in diagnosis and prevention as well as in individualized treatment aspects of osteoporosis.