Magnetic resonance spectroscopy and molecular studies in ornithine transcarbamylase deficiency novel mutation c.802A>G in exon 8 (p.Met268Val)

Neurol Neurochir Pol. 2013 May-Jun;47(3):283-9. doi: 10.5114/ninp.2013.35488.


Ornithine transcarbamylase (OTC) deficiency, an X-linked, semidominant disorder, is the most common inherited de-fect in ureagenesis, resulting in hyperammonaemia type II. The OTC gene, localised on chromosome X, has been mapp-ed to band Xp21.1, proximate to the Duchenne muscular dystrophy (DMD) gene. More than 350 different mutations, including missense, nonsense, splice-site changes, small de-letions or insertions and gross deletions, have been describ-ed so far. Almost all mutations in consensus splicing sites confer a neonatal phenotype. Most mutations in the OTC gene are 'private' and are distributed throughout the gene with a paucity of mutation in the sequence encoding the leader peptide (exon 1 and beginning of exon 2) and in exon 7. They have familial origin or occur de novo. Even with sequencing of the entire reading frame and exon/intron boundaries, only about 80% of the mutations are detected in patients with proven OTC deficiency. The remainder probably occur within the introns or in regulatory domains. The authors present a 4-year-old boy with the unreported missense mutation c.802A>G. The nucleotide transition leads to amino acid substitution Met to Val at codon 268 of the OTC protein.

Publication types

  • Case Reports

MeSH terms

  • Child, Preschool
  • Humans
  • Magnetic Resonance Imaging
  • Magnetic Resonance Spectroscopy
  • Male
  • Mutation*
  • Ornithine Carbamoyltransferase / genetics*
  • Ornithine Carbamoyltransferase Deficiency Disease / diagnosis*
  • Ornithine Carbamoyltransferase Deficiency Disease / genetics*


  • Ornithine Carbamoyltransferase