Coenzyme Q 10 defects may be associated with a deficiency of Q 10 -independent mitochondrial respiratory chain complexes

Biological research: BR

Samira Ait-El-Mkadem¹  ois Benoist²  Annabelle Chaussenot²  Cé²  Jean-Franç³  Sylvie Bannwarth³  cile Rouzier³  Konstantina Fragaki³ 

[1] Department of Biochemistry, Robert Debre Hospital, Paris, France;Department of Medical Genetics, Nice Teaching Hospital, National Centre for Mitochondrial Diseases, Nice, France;School of Medicine, IRCAN, UMR CNRS 7284/INSERM U1081/UNS, Nice Sophia-Antipolis University, Nice Cedex 2, France

关键词: Mitochondrial disease;    CoQ10 deficiency;    Respiratory chain;    Spectrophotometry;    LC-MSMS;   

DOI  :  10.1186/s40659-015-0065-0

学科分类：生物科学（综合）

来源: BioMed Central

【 摘 要 】

Coenzyme Q10 (CoQ10 or ubiquinone) deficiency can be due either to mutations in genes involved in CoQ10 biosynthesis pathway, or to mutations in genes unrelated to CoQ10 biosynthesis. CoQ10 defect is the only oxidative phosphorylation disorder that can be clinically improved after oral CoQ10 supplementation. Thus, early diagnosis, first evoked by mitochondrial respiratory chain (MRC) spectrophotometric analysis, then confirmed by direct measurement of CoQ10 levels, is of critical importance to prevent irreversible damage in organs such as the kidney and the central nervous system. It is widely reported that CoQ10 deficient patients present decreased quinone-dependent activities (segments I + III or G3P + III and II + III) while MRC activities of complexes I, II, III, IV and V are normal. We previously suggested that CoQ10 defect may be associated with a deficiency of CoQ10-independent MRC complexes. The aim of this study was to verify this hypothesis in order to improve the diagnosis of this disease. To determine whether CoQ10 defect could be associated with MRC deficiency, we quantified CoQ10 by LC-MSMS in a cohort of 18 patients presenting CoQ10-dependent deficiency associated with MRC defect. We found decreased levels of CoQ10 in eight patients out of 18 (45 %), thus confirming CoQ10 disease. Our study shows that CoQ10 defect can be associated with MRC deficiency. This could be of major importance in clinical practice for the diagnosis of a disease that can be improved by CoQ10 supplementation.

【 授权许可】

CC BY