Related Experiment Videos
Hypophosphatasia presenting with pyridoxine-responsive seizures, hypercalcemia, and pseudotumor cerebri: case report
Hüseyin Demirbilek1, Yasemin Alanay, Ayfer Alikaşifoğlu
1Hacettepe University Faculty of Medicine, Department of Pediatrics Endocrinology, Ankara, Turkey. dr_huseyin@hotmail.com
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.
Related Concept Videos
Inborn Errors of Metabolism
Introduction to Electrolytes
Role of Sodium
One...
Protein Kinases and Phosphatases
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
Graves Disease II: Pathophysiology
Lysosomal Hydrolases
Phosphorylation
During phosphorylation, protein kinases transfer the terminal phosphate group of ATP to specific amino acid side chains of substrate proteins. Serine, threonine, and tyrosine are the most commonly...