Mondo Description Hypophosphatasia (HPP) is a rare heritable metabolic disorder characterized by defective mineralization of bone and/or teeth in the presence of reduced activity of unfractionated serum alkaline phosphatase (ALP). The clinical spectrum is extremely wide, from stillbirth at one end to fractures of the lower extremities in adulthood, at the other, or even no bone manifestations (odontohypophosphatasia).

Uniprot Description A metabolic bone disease characterized by defective skeletal mineralization and biochemically by deficient activity of the tissue non-specific isoenzyme of alkaline phosphatase. Four forms are distinguished, depending on the age of onset: perinatal, infantile, childhood and adult type. The perinatal form is the most severe and is almost always fatal. The adult form is mild and characterized by recurrent fractures, osteomalacia, rickets, and loss of teeth. Some cases are asymptomatic, while some patients manifest dental features without skeletal manifestations (odontohypophosphatasia).