Thelansis

  Hypophosphatasia (HPP) is the inborn error of metabolism caused by a loss-of-function mutation(s) in the gene that encodes the tissue-nonspecific isozyme of alkaline phosphatase (TNAP). The disease has been classified according to patient age when the first signs and symptoms manifest, i.e., perinatal, infantile, childhood, adult HPP. Other types include odonto HPP and perinatal benign. Babies with the perinatal/immature forms of HPP often die with severe rickets and respiratory insufficiency and sometimes hypercalcemia and vitamin B6-responsive seizures. The primary biochemical defect in HPP is a deficiency of TNAP activity that leads to elevated circulating levels of substrates, in particular inorganic pyrophosphate (PPi), a potent calcification inhibitor. The clinical severity of HPP varies greatly. The disease can be classified according to patient age when the first signs and symptoms manifest: perinatal, infantile, childhood, and adult HPP. Additional clinical forms include...