Hypophosphatasia diagnosis in adults: clinical case and literature review

Hypophosphatasia (HPP) is an inherited metabolic disease characterized by low activity of tissue non-specific alkaline phosphatase (TNAP) due to mutations in the ALPL gene [1]. The low activity of TNAP leads to the systematic accumulation of its substrates, namely inorganic pyrophosphate (PPi), a strong inhibitor of mineralization, and pyridoxal-5’-phosphate (PLP), a cofactor of several enzymes, which largely explain the musculoskeletal and systemic features of the disease. Hypophosphatasia is characterized by a wide range of manifestations and varying degrees of severity: from asymptomatic course in carriers of the ALPL mutation to intrauterine death in perinatal form. This article will discuss the manifestation of the disease in adulthood, which requires differential diagnosis with postmenopausal osteoporosis.