A fatal case of COQ7-associated primary coenzyme Q 10 deficiency

JIMD Rep. 2019 Apr 3;47(1):23-29. doi: 10.1002/jmd2.12032. eCollection 2019 May.


Background: Primary coenzyme Q10 (CoQ10) deficiencies are clinically and genetically heterogeneous group of disorders associated with defects of genes involved in the CoQ10 biosynthesis pathway. COQ7-associated CoQ10 deficiency is very rare and only two cases have been reported.

Methods and results: We report a patient with encephalo-myo-nephro-cardiopathy, persistent lactic acidosis, and basal ganglia lesions resulting in early infantile death. Using whole exome sequencing, we identified compound heterozygous variants in the COQ7 gene consisting of a deletion insertion resulting in frameshift [c.599_600delinsTAATGCATC, p.(Lys200Ilefs*56)] and a missense substitution [c.319C>T, p.(Arg107Trp), NM_016138.4]. Skin fibroblast studies showed decreased combined complex II + III activity and reduction in CoQ10 level.

Conclusion: This third patient presenting with lethal encephalo-myo-nephro-cardiopathy represents the severe end of this ultra-rare mitochondrial disease caused by biallelic COQ7 mutations. The response to CoQ10 supplement is poor and alternative treatment strategies should be developed for a more effective management of this disorder.

Keywords: COQ7; CoQ10; CoQ10 supplementation; coenzyme Q10; encephalo‐myo‐nephro‐cardiopathy; mitochondrial disease.

Publication types

  • Case Reports