@article {1263341,
	title = {Systemic Manifestations in Pyridox(am)ine 5{\textquoteright}-Phosphate Oxidase Deficiency},
	journal = {Pediatr Neurol},
	volume = {76},
	year = {2017},
	month = {2017 Nov},
	pages = {47-53},
	abstract = {OBJECTIVE: Pyridoxine is converted to its biologically active form pyridoxal-5-phosphate (P5P) by the enzyme pyridox(am)ine 5{\textquoteright}-phosphate oxidase and serves as a cofactor in nearly 200 reactions in the central nervous system. Pyridox(am)ine 5{\textquoteright}-phosphate oxidase deficiency leads to P5P dependent epilepsy, typically a neonatal- or infantile-onset epileptic encephalopathy treatable with P5P or in some cases, pyridoxine. Following identification of retinopathy in a patient with pyridox(am)ine 5{\textquoteright}-phosphate oxidase deficiency that was reversible with P5P therapy, we describe the systemic manifestations of pyridox(am)ine 5{\textquoteright}-phosphate oxidase deficiency. METHODS: A series of six patients with homozygous mutations of PNPO, the gene coding pyridox(am)ine 5{\textquoteright}-phosphate oxidase, were evaluated in our center over the course of two years for phenotyping of neurological and systemic manifestations. RESULTS: Five of six were born prematurely, three had anemia and failure to thrive, and two had elevated alkaline phosphatase. A movement disorder was observed in two children, and a reversible retinopathy was observed in the most severely affected infant. All patients had neonatal-onset epilepsy and were on a continuum of developmental delay to profound encephalopathy. Electroencephalographic features included background slowing and disorganization, absent sleep features, and multifocal and generalized epileptiform discharges. All the affected probands carried a homozygous PNPO mutation (c.674\&nbsp;G\&gt;T, c.686\&nbsp;G\&gt;A and c.352G\&gt;A). CONCLUSION: In addition to the well-described epileptic encephalopathy, pyridox(am)ine 5{\textquoteright}-phosphate oxidase deficiency causes a range of neurological and systemic manifestations. A movement disorder, developmental delay, and encephalopathy, as well as retinopathy, anemia, and failure to thrive add to the broadening clinical spectrum of P5P dependent epilepsy.},
	issn = {1873-5150},
	doi = {10.1016/j.pediatrneurol.2017.05.024},
	author = {Guerriero, R{\'e}jean M and Patel, Archana A and Walsh, Brian and Baumer, Fiona M and Shah, Ankoor S and Peters, Jurriaan M and Rodan, Lance H and Agrawal, Pankaj B and Pearl, Phillip L and Takeoka, Masanori}
}
