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Epigenetics, epidemiology and mitochondrial DNA diseases
Patrick F Chinnery1, Hannah R Elliott, Gavin Hudson
1Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne NE1 3BZ, UK. patrick.chinnery@ncl.ac.uk
International Journal of Epidemiology
|January 31, 2012
Summary
Epigenetic factors may explain incomplete penetrance in mitochondrial DNA (mtDNA) diseases. Emerging evidence suggests mitochondria can epigenetically modify mtDNA, influencing disease presentation and contributing to varied pathophysiology.
Area of Science:
- Genetics and Epigenetics
- Mitochondrial Biology
- Human Disease Pathogenesis
Background:
- Mitochondrial DNA (mtDNA) mutations are a significant cause of inherited human diseases, affecting at least 1 in 10,000 adults.
- Pathogenic mtDNA mutations are prevalent in the general population (1 in 200), yet disease penetrance is often incomplete and variable, even within families.
- Current understanding of mtDNA disease pathogenesis, incomplete penetrance, and phenotypic variability remains incomplete, despite genetic and biochemical studies.
Purpose of the Study:
- To review the potential role of epigenetic factors in the pathogenesis of mitochondrial DNA diseases.
- To explore how epidemiological approaches can enhance understanding of mtDNA-related disorders.
- To investigate the emerging evidence for epigenetic modifications within mitochondria and their impact on disease.
Main Methods:
- Literature review of genetic, biochemical, and emerging epigenetic studies on mitochondrial DNA diseases.
- Analysis of epidemiological data to understand population and family-level disease penetrance.
- Synthesis of evidence regarding mitochondrial epigenetic machinery and reactive oxygen species (ROS) effects.
Main Results:
- Mitochondria possess machinery capable of epigenetically modifying mtDNA expression, challenging previous assumptions.
- Increased reactive oxygen species (ROS) in mtDNA diseases can induce epigenetic changes in the nuclear genome, including DNA methylation and microRNA expression.
- These epigenetic modifications contribute to the diverse pathophysiology and incomplete penetrance observed in mitochondrial diseases.
Conclusions:
- Epigenetic mechanisms, including mtDNA methylation and nuclear genome alterations, are crucial for understanding the incomplete penetrance and phenotypic variability of mitochondrial DNA diseases.
- Future research should focus on investigating the role of mtDNA methylation in human disease.
- Epidemiological studies combined with epigenetic analyses offer a promising avenue for comprehensive understanding of these complex disorders.
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