Alkaline phosphatase
The severity of symptoms ranges from premature loss of deciduous teeth with no bone abnormalities to stillbirth depending upon which amino acid is changed in the ALPL gene. Mutations in the ALPL gene lead to varying low activity of the enzyme tissue-nonspecific alkaline phosphatase (TNSALP) resulting in hypophosphatasia (HPP). There are different clinical forms of HPP which can be inherited by an autosomal recessive trait or autosomal dominant trait, the former causing more severe forms of the disease. Alkaline phosphatase allows for mineralization of calcium and phosphorus by bones and teeth. ALPL gene mutation leads to insufficient TNSALP enzyme 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.