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Visualization of Mitochondrial Respiratory Function using Cytochrome C Oxidase / Succinate Dehydrogenase (COX/SDH) Double-labeling Histochemistry
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Genetic bases of mitochondrial respiratory chain disorders

Agnès Rötig1

  • 1Inserm U781, hôpital Necker-Enfants Malades, université Paris Descartes, 149, rue de Sèvres, 75015 Paris, France. agnes.Rotig@inserm.fr

Diabetes & Metabolism
|January 23, 2010
PubMed

Insights

Respiratory chain (RC) deficiency can cause diverse symptoms due to its dual genetic origin. Growing evidence shows nuclear gene mutations, not just mitochondrial DNA, are key causes of RC disorders.

Area of Science:

  • Biochemistry
  • Genetics
  • Cellular Respiration

Background:

  • Oxidative phosphorylation, driven by the respiratory chain (RC), generates ATP, essential for cellular energy. This process is fully functional at birth.
  • The dual genetic origin of RC components (nuclear and mitochondrial DNA) theoretically allows for any symptom, in any organ, at any age, with any inheritance pattern.

Purpose of the Study:

  • To highlight the expanding understanding of respiratory chain (RC) disorders.
  • To emphasize the growing number of identified disease-causing mutations in nuclear genes, challenging the historical focus on mitochondrial DNA (mtDNA).

Main Methods:

  • Review of existing literature on RC disorders.
  • Analysis of genetic origins of RC components.
  • Comparison of historical and current etiological findings in RC deficiencies.

Main Results:

  • Historically, RC disorders were primarily attributed to mitochondrial DNA (mtDNA) mutations.
  • The number of identified disease-causing mutations in nuclear genes is increasing significantly.
  • Nuclear genes encode not only RC subunits but also crucial proteins for holoenzyme biogenesis and mtDNA metabolism.

Conclusions:

  • RC disorders are genetically complex, arising from both nuclear and mitochondrial DNA.
  • The etiological landscape of RC disorders is shifting, with a greater recognition of nuclear gene involvement.
  • Comprehensive genetic analysis is crucial for diagnosing RC deficiencies.

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