ALPL and hypophosphatasia: Genetic mutations in TNAP coding gene has been proven to participate in development of a genetic disease called hypophosphatasia (OMIM: 171760) that results in bone undermineralization and is indicative of the ALP role in calcification.34 Missense mutations in TNAP gene causes decreased or complete absence of ALP activity; leads to increased levels of TNAP substrates such as inorganic pyrophosphate (PPi), phosphoethanolamine, and pyridoxal-5’-phosphate.