title: Hypophosphatasia presenting with pyridoxine-responsive seizures, hypercalcemia, and pseudotumor cerebri: case report.
abstract: Hypophosphatasia (HPP) is an inborn error of metabolism characterized by defective bone mineralization caused by a deficiency in alkaline phosphatase (ALP) activity due to mutations in the tissue-nonspecific ALP (TNALP) gene. The clinical expression of the disease is variable. Six forms of HPP are identified according to age at presentation and clinical features. Patients with the infantile form are normal at birth. First symptoms appear within the first 6 months of life. Along with skeletal findings, HPP patients may present with hypercalcemia, seizures, pseudotumor cerebri, and pulmonary insufficiency. Seizures in HPP are refractory to conventional antiepileptic drugs, but are responsive to pyridoxine. Herein, we report a case of HPP who presented with pyridoxine-responsive seizures in the early neonatal period and was found to have hypercalcemia, skeletal demineralization and increased intracranial pressure.
authors.affiliation: Hacettepe University Faculty of Medicine, Department of Pediatrics Endocrinology, Ankara, Turkey. dr_huseyin@hotmail.com
authors.forename: Hüseyin
authors.initials: H
authors.lastname: Demirbilek
authors.forename: Yasemin
authors.initials: Y
authors.lastname: Alanay
authors.forename: Ayfer
authors.initials: A
authors.lastname: Alikaşifoğlu
authors.forename: Meral
authors.initials: M
authors.lastname: Topçu
authors.forename: Etienne
authors.initials: E
authors.lastname: Mornet
authors.forename: Nazlı
authors.initials: N
authors.lastname: Gönç
authors.forename: Alev
authors.initials: A
authors.lastname: Özön
authors.forename: Nurgün
authors.initials: N
authors.lastname: Kandemir
mesh_terms: D000469:Alkaline Phosphatase / Q000235:genetics; D003241:Consanguinity; D003937:Diagnosis, Differential; D017809:Fatal Outcome; D006720:Homozygote; D006801:Humans; D006934:Hypercalcemia / Q000175:diagnosis* / Q000209:etiology; D007014:Hypophosphatasia / Q000150:complications / Q000175:diagnosis* / Q000235:genetics; D007223:Infant; D008297:Male; D009154:Mutation; D011559:Pseudotumor Cerebri / Q000175:diagnosis* / Q000209:etiology; D011736:Pyridoxine / Q000627:therapeutic use; D012640:Seizures / Q000175:diagnosis* / Q000188:drug therapy / Q000209:etiology
chemical_list: D000469:Alkaline Phosphatase; D011736:Pyridoxine