Systemic Manifestations in Pyridox(am)ine 5'-Phosphate Oxidase Deficiency.

Published

Journal Article

OBJECTIVE: Pyridoxine is converted to its biologically active form pyridoxal-5-phosphate (P5P) by the enzyme pyridox(am)ine 5'-phosphate oxidase and serves as a cofactor in nearly 200 reactions in the central nervous system. Pyridox(am)ine 5'-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'-phosphate oxidase deficiency that was reversible with P5P therapy, we describe the systemic manifestations of pyridox(am)ine 5'-phosphate oxidase deficiency. METHODS: A series of six patients with homozygous mutations of PNPO, the gene coding pyridox(am)ine 5'-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 G>T, c.686 G>A and c.352G>A). CONCLUSION: In addition to the well-described epileptic encephalopathy, pyridox(am)ine 5'-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.

Full Text

Duke Authors

Cited Authors

  • Guerriero, RM; Patel, AA; Walsh, B; Baumer, FM; Shah, AS; Peters, JM; Rodan, LH; Agrawal, PB; Pearl, PL; Takeoka, M

Published Date

  • November 2017

Published In

Volume / Issue

  • 76 /

Start / End Page

  • 47 - 53

PubMed ID

  • 28985901

Pubmed Central ID

  • 28985901

Electronic International Standard Serial Number (EISSN)

  • 1873-5150

Digital Object Identifier (DOI)

  • 10.1016/j.pediatrneurol.2017.05.024

Language

  • eng

Conference Location

  • United States