ACOX2 deficiency: A disorder of bile acid synthesis with transaminase elevation, liver fibrosis, ataxia, and cognitive impairment

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Vilarinho S., SARI S., Mazzacuva F., Bilguvar K., Esendagli-Yilmaz G., Jain D., ...More

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, vol.113, no.40, pp.11289-11293, 2016 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 113 Issue: 40
  • Publication Date: 2016
  • Doi Number: 10.1073/pnas.1613228113
  • Journal Name: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.11289-11293
  • Keywords: branched-chain acyl-CoA oxidase, bile acid metabolism, peroxisomal disorder, whole-exome sequencing, idiopathic liver disease, ACYL-COA OXIDASE, ZELLWEGER-SYNDROME, MUTATIONS, DISEASE, DIAGNOSIS, BIOSYNTHESIS, FAILURE, ONSET
  • Gazi University Affiliated: Yes

Abstract

Acyl CoA Oxidase 2 (ACOX2) encodes branched-chain acyl-CoA oxidase, a peroxisomal enzyme believed to be involved in the metabolism of branched-chain fatty acids and bile acid intermediates. Deficiency of this enzyme has not been described previously. We report an 8-y-old male with intermittently elevated transaminase levels, liver fibrosis, mild ataxia, and cognitive impairment. Exome sequencing revealed a previously unidentified homozygous premature termination mutation (p.Y69*) in ACOX2. Immunohistochemistry confirmed the absence of ACOX2 expression in the patient's liver, and biochemical analysis showed marked elevation of intermediate bile acids upstream of ACOX2. These findings define a potentially treatable inborn error of bile acid biosynthesis caused by ACOX2 deficiency.