Pediatric hypophosphatasia: avoid diagnosis missteps!

The article focuses on pediatric hypophosphatasia (HPP), a rare inherited metabolic bone disease caused by mutations in the ALPL gene encoding the tissue-nonspecific isoenzyme of alkaline phosphatase (TNSALP). It highlights diagnostic challenges through a case study of a young boy whose diagnosis was delayed due to misinterpretation of clinical signs, radiographic findings, and biochemical tests, including inappropriate reference ranges and off-target assays. The biochemical signature of HPP includes low serum alkaline phosphatase (hypophosphatasemia) and elevated substrates of TNSALP such as phosphoethanolamine (PEA) and pyridoxal 5-phosphate (PLP), while radiographic and dental features like premature loss of deciduous teeth with intact roots are key clinical clues. The article emphasizes the importance of age-appropriate laboratory reference ranges, comprehensive clinical evaluation, and ALPL genetic testing to support diagnosis and guide management, noting recent advances such as enzyme replacement therapy with asfotase alfa.