Pseudotumor Cerebri as a Rare Presentation of Infantile Hypophosphatasia: A Case Report

ABSTRACT Objective: We are reporting a case of infantile hypophosphatasia (HPP) in a patient who presented with pseudotumor cerebri (PTC). This is an extremely rare clinical condition to present during infancy, much less secondary to a rare etiology such as HPP. Methods: The clinical, laboratory, radiologic, and genetic findings are presented with a brief review of the literature. Results: A female infant presented with symptoms suggestive of increased intracranial pressure and hypotonia. Her brain magnetic resonance imaging (MRI) and magnetic resonance venography were normal, but her cerebrospinal fluid (CSF) pressure was very high (77 cm). We diagnosed her with PTC. Work up revealed HPP, and genetic analysis revealed a homozygous mutation in c.214A>G (p.I72V). Among only 4 other cases reported in the literature, our case is unique in that it had the highest CSF pressure ever reported with such a rare association; in addition, our patient had the youngest age of presentation. Conclusion: HPP can present with infantile PTC. Early diagnosis and management may modify the clinical course, particularly the visual complications. Abbreviations: CSF cerebrospinal fluid HPP hypophosphatasia PTC pseudotumor cerebri TNALP tissue nonspecific alkaline phosphatase