The explosive growth in the field of molecular biology over the last two decades has started to make a great impact on clinical medicine. Genes have been cloned for diseases that were poorly understood only a decade ago. Additionally, investigators are increasingly aware that there are strong genetic components to complex disorders, such as osteoporosis, that are not classically thought of as genetic disorders. New insights into the pathogenesis of metabolic bone diseases have been obtained from investigations into the molecular biology of these diseases and new therapies will become available based on these new insights. In The Genefies of Osteoporosis and Metabolie Bane Disease, I have assembled an internationally renowned group of experts to write the various chapters. Each of the authors is an expert in his/her field who is currently performing research on the content of their chapter and have made important contributions to the understanding of the clinical fea­ tures and pathophysiology of metabolic bone disease and genetics. The first part of The Genefies of Osteoporosis and Metabolie Bane Disease addresses issues related to genetic contributions to the development of osteoporosis and the many factors that must be considered when searching for genesthat predispose to osteoporosis. The second sec­ tion addresses recent advances in the clinical and molecular biological aspects of inherited metabolic bone disorders. The last section reviews the latest techniques for finding genes that predispose to metabolic bone diseases.