Bone disorders are common and represent a major burden on health economic costs. Our understanding of bone development has had tremendous advances in the last ten year due primarily to focusing on genetics. For example, osteoporosis and related fractures are the leading cause of hospital admission in women over the age of 50 years, and >80% of adults over 55 years of age will suffer from osteoarthritis. Treatments of some metabolic disorders have been greatly improved by an increased understanding of bone biology which has been facilitated by advances in unravelling the genetics underlying bone disorders. These interactions between bone biology / physiology and genetics have also greatly enhanced the understanding of normal bone function as well as the molecular pathogenesis of metabolic bone disorders.