Intestinal, placental, placental-like, and liver/bone/kidney (tissue-nonspecific) all belong to alkaline phosphatases. 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. This enzyme has been linked directly to hypophosphatasia disorder characterized by hypercalcemia and skeletal defects. Alkaline phosphatase allows for mineralization of calcium and phosphorus by bones and teeth. ALPL gene mutation leads to insufficient enzyme tissue-nonspecific alkaline phosphatase and allows for an accumulation of chemicals such as inorganic pyrophosphate to indirectly cause elevated calcium levels in the body and lack of bone calcification.