Odontohypophosphatasia is the mildest form of hypophosphatasia that manifests as tooth dysplasia and/or early loss of deciduous or permanent teeth. Odontohypophosphatasia is a form of Hypophosphatasia (see also HPP) with primarily only dental manifestations, in the absence of skeletal system abnormalities, such as rickets or osteomalacia. About 150 cases have been reported to date. Autosomal recessive and autosomal dominant patterns of inheritance are reported in odonto-HPP. This disease may affect both children and adults, and it is caused by heterozygous mutation in the gene encoding tissue-nonspecific alkaline phosphatase (ALPL), with generalized reduction of activity of the tissue-non-specific (liver/bone/kidney) isoenzyme of ALP (TNSALP). Dental X-rays show reduced alveolar bone and enlarged pulp chambers and root canals.