Hypophosphatasia in Adults: Clinical Assessment and Treatment Considerations

Hypophosphatasia (HPP) is a rare inherited disorder of bone affecting approximately 500 to 600 known individuals in the United States. HPP is the result of mutations involving the gene for tissue nonspecific alkaline phosphatase. Five clinical types of HPP are recognized. The clinical presentation of HPP varies from devastating prenatal intrauterine disease to mild manifestations in adulthood. In adults, main clinical involvement includes early loss of primary or secondary teeth, osteoporosis, bone pain, chondrocalcinosis, and fractures. Treatment for HPP is limited. Asfotase alfa is a subcutaneously administered synthetic human alkaline phosphatase that is approved for treatment of patients, including adults, with perinatal/infantile- and juvenile-onset HPP. However, guidelines for the treatment of adults with HPP are not available. This discussion addresses diagnostic and treatment considerations for adults with HPP.