Classification of Disorders of Bone and Calcium Metabolism.

Classification is a natural human trait that enables us to put what may otherwise be very complex subjects into some order. However, classification should be seen not as an end in itself but rather as a means to help us understand certain topics. In the case of medicine, classification helps to provide information about the causes underlying many of the conditions encountered and, in some cases, provides a rationale for developing new treatments. This chapter aims to provide a helpful (if complex) classification of diseases of bone and calcium and, where known, to describe the underlying genetic mechanisms.