PNPO deficiency: an under diagnosed inborn error of pyridoxine metabolism

Mol Genet Metab. 2008 Aug;94(4):431-434. doi: 10.1016/j.ymgme.2008.04.008. Epub 2008 May 15.

Abstract

The rare autosomal recessive disorder pyridoxine 5'-phosphate oxidase (PNPO) deficiency is a recently described cause of neonatal and infantile seizures. Clinical evaluation, and biochemical and genetic testing, were performed on a neonate with intractable seizures who did not respond to anticonvulsant drugs and pyridoxine. Sequencing of the PNPO gene revealed a novel homozygous c.284G>A transition in exon 3, resulting in arginine to histidine substitution and reduced activity of the PNPO mutant to 18% relative to the wild type. This finding enabled molecular prenatal diagnosis in a subsequent pregnancy, accurate genetic counseling in the large inbred family, and population screening.

MeSH terms

  • Amino Acid Substitution
  • Animals
  • Brain Diseases, Metabolic, Inborn / diagnosis
  • Brain Diseases, Metabolic, Inborn / enzymology*
  • Brain Diseases, Metabolic, Inborn / genetics
  • Brain Diseases, Metabolic, Inborn / metabolism*
  • CHO Cells
  • Codon, Nonsense
  • Consanguinity
  • Cricetinae
  • Cricetulus
  • DNA Mutational Analysis
  • Exons
  • Female
  • Gene Expression
  • Genetic Testing
  • Humans
  • Infant, Newborn
  • Male
  • Mutagenesis, Site-Directed
  • Pedigree
  • Point Mutation
  • Prenatal Diagnosis
  • Pyridoxaminephosphate Oxidase / deficiency*
  • Pyridoxaminephosphate Oxidase / genetics
  • Pyridoxine / metabolism*
  • Seizures / diagnosis
  • Seizures / enzymology
  • Seizures / genetics
  • Seizures / metabolism

Substances

  • Codon, Nonsense
  • Pyridoxaminephosphate Oxidase
  • Pyridoxine