Introduction: Hypophosphatasia is a rare inborn error of metabolism caused by mutations in the gene encoding the tissue-nonspecific isoenzyme of alkaline phosphatase (TNSALP). Alterations in the TNSALP gene lead to low alkaline phosphatase activity levels and ultimately to rickets, osteomalacia, or both, which characterize this disorder. Clinical presentation varies widely, from death in utero to cases in which pathologic fractures first present in adulthood.
Materials and methods: A 39 years old woman with history of difficulty in fracture healing. At the age of 13, after a fall from her stature, she was diagnosed with femur fracture. The patient was treated conservative for 3 months and the healing process wasn`t satisfying. She was consulted in Germany where low levels of alkaline phosphatase and Vit. D-total were found. The full blood count and biochemistry was normal as well as the levels of bone markers and parathyroid hormone. There are no findings for rickets in her childhood.
Results: The woman underwent a series of operations. In 1990 a correcting osteotomy and osteosynthesis with plate were performed. Years later the patient suffered from a pathological fracture located proximal from the plate. The femur fracture was treated in the year of 1993 with application of a Küntscher nail. The last operation was performed in 2014 when a bone graft and a metal screw were placed in the great trochanter. The same patient underwent CT in 2016 due to pain in the right tibia with suspicion of pathological changes.
Conclusion: Patients with hypophosphatasia may present with varying signs and symptoms, history, and hereditary patterns. Differential diagnosis with Achondrogenesis, Osteogenesis imeprfecta and rickets must be performed for early diagnosis and treatment.
