Hypophosphatasia: Clinical Clues and Management Considerations

This case report identifies typical manifestations of a patient with hypophosphatasia, a rare genetic condition in which mutations in tissue-non-specific alkaline phosphatase (TNSALP) enzymes cause low levels of alkaline phosphatase and defective bone mineralization. It explores common diagnostic clues from the history and laboratory evaluation, which can help clinicians identify the disorder. This case introduces a 49-year-old patient with a long history of fractures and dental abnormalities who was referred to endocrinology for evaluation of osteopenia. Further review of her laboratory data was noteworthy for a low level of alkaline phosphatase. Additionally, a low vitamin B6 level was measured, and genetic testing was ultimately diagnostic for hypophosphatasia. The patient was started on the anabolic agent teriparatide but was lost to subsequent follow-up. This case discusses additional management considerations, which are currently limited but continue to evolve, and cautions against bisphosphonate use in the setting of hypophosphatasia.