In Silico Analysis of a de Novo OTC Variant as a Cause of Ornithine Transcarbamylase Deficiency

Ozdemir Y., Cag M., Gul Ş., Yüksel Z., Ergoren M. C.

Applied Immunohistochemistry and Molecular Morphology, vol.30, no.2, pp.153-156, 2022 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 30 Issue: 2
  • Publication Date: 2022
  • Doi Number: 10.1097/pai.0000000000000979
  • Journal Name: Applied Immunohistochemistry and Molecular Morphology
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, BIOSIS, Biotechnology Research Abstracts, EMBASE, MEDLINE
  • Page Numbers: pp.153-156
  • Keywords: in silico analysis, liver transplantation, ornithine transcarbamylase deficiency, OTC, whole-exome sequencing
  • Bezmialem Vakıf University Affiliated: No


Ornithine transcarbamylase deficiency (OTCD) is the most common X-linked hereditary disorder of urea cycle disorders that is caused by neonatal hyperammonemia. OTC gene sequence variations are common causes of OTCD. The current study presents a 28-month-old baby girl proband with phenotypical characteristics of OTCD such as irritability, somnolence, intermittent vomiting, and high levels of serum ammonium. Whole-exome sequencing revealed a de novo c.275G>A p.(Arg92Gln) variant within the OTC gene. In silico analysis revealed a possible differential affinity between wild-type and mutant OTCase, while Arg92Gln decreases the binding ability of OTCase to the substrate, which can disrupt the urea cycle and explains the molecular pathogenicity of clinical hyperammonemia. In light of the fact that the genotype and phenotype correlation of OTCD is still uncertain, the present in silico analysis outcome can enhance our knowledge on this complicated, rare, and severe genetic disorder.