Enzyme replacement therapy for congenital hypophosphatasia allows for surgical treatment of related complex craniosynostosis: a case series

Hypophosphatasia (HPP) is a rare inherited disorder of bone metabolism that results in the loss of function of the gene coding for tissue-nonspecific alkaline phosphatase (TNSALP). Patients with HPP have defective bone mineralization as well as craniosynostosis that can be seen in the infantile and childhood forms of this disease. Traditionally, HPP has had a poor prognosis, with few children surviving to exhibit the phenotype of clinical craniosynostosis that requires surgical intervention. Here, the authors report on new advancements in enzyme replacement therapy (ERT) for children affected by HPP, allowing these patients to survive and undergo surgery to address complex craniosynostosis. The authors discuss their case series of 4 HPP patients treated at their institution with ERT who have undergone successful surgical intervention for craniosynostosis. These children had no complications related to their surgeries and exhibited decreased neurological symptoms following cranial vault remodeling. This study reveals that ERT administered either pre- or post-operatively paired with cranial vault remodeling strategies can yield improved neurological outcomes in children affected by HPP.