ALPL

There are at least four distinct but related alkaline phosphatases: intestinal, placental, placental-like, and liver/bone/kidney (tissue-nonspecific) . The first three are located together on chromosome 2, whereas the tissue-nonspecific form is located on chromosome 1. The product of this gene is a membrane-bound glycosylated enzyme that is not expressed in any particular tissue and is, therefore, referred to as the tissue-nonspecific form of the enzyme. The exact physiological function of the alkaline phosphatases is not known. A proposed function of this form of the enzyme is matrix mineralization. However, mice that lack a functional form of this enzyme show normal skeletal development.