Related Experiment Video
Updated: Apr 4, 2026
Measuring Single-Cell Mitochondrial DNA Copy Number and Heteroplasmy Using Digital Droplet Polymerase Chain Reaction
Published on: July 12, 2022
Mitochondrial DNA Heteroplasmy Associations With Neurosensory and Mobility Function in Elderly Adults
Gregory J Tranah1, Kristine Yaffe2, Shana M Katzman3
1California Pacific Medical Center Research Institute, San Francisco. gtranah@sfcc-cpmc.net.
Background:
Mitochondrial DNA (mtDNA) heteroplasmy is a mixture of normal and mutated mtDNA molecules in a cell. High levels of heteroplasmy at specific mtDNA sites lead to inherited mitochondrial diseases with neurological, sensory, and movement impairments. Here we test the hypothesis that heteroplasmy levels in elderly adults are associated with impaired function resembling mild forms of mitochondrial disease.
Methods:
We examined platelet mtDNA heteroplasmy at 20 disease-causing sites for associations with neurosensory and mobility function among 137 participants from the community-based Health, Aging, and Body Composition Study.
Results:
Elevated mtDNA heteroplasmy at four mtDNA sites in complex I and tRNA genes was nominally associated with reduced cognition, vision, hearing, and mobility: m.10158T>C with Modified Mini-Mental State Examination score (p = .009); m.11778G>A with contrast sensitivity (p = .02); m.7445A>G with high-frequency hearing (p = .047); and m.5703G>A with 400 m walking speed (p = .007).
Conclusions:
These results indicate that increased mtDNA heteroplasmy at disease-causing sites is associated with neurosensory and mobility function in older persons. We propose the novel use of mtDNA heteroplasmy as a simple, noninvasive predictor of age-related neurologic, sensory, and movement impairments.
Insights
Mitochondrial DNA (mtDNA) heteroplasmy in older adults is linked to declines in cognitive, sensory, and mobility functions. This finding suggests mtDNA heteroplasmy may predict age-related impairments.
Area of Science:
- Genetics
- Aging Research
- Neuroscience
Background:
- Mitochondrial DNA (mtDNA) heteroplasmy, a mix of normal and mutated mtDNA, can cause inherited mitochondrial diseases.
- High levels of heteroplasmy are associated with neurological, sensory, and movement impairments.
Purpose of the Study:
- To investigate the association between mtDNA heteroplasmy levels and functional impairments in elderly adults.
- To determine if mtDNA heteroplasmy predicts age-related functional decline.
Main Methods:
- Examined platelet mtDNA heteroplasmy at 20 disease-associated sites in 137 participants from the Health, Aging, and Body Composition Study.
- Assessed associations between heteroplasmy levels and neurosensory and mobility functions.
Main Results:
- Elevated heteroplasmy at four specific mtDNA sites (m.10158T>C, m.11778G>A, m.7445A>G, m.5703G>A) showed nominal associations with reduced cognition, vision, hearing, and walking speed.
- These sites are located in complex I and tRNA genes.
Conclusions:
- Increased mtDNA heteroplasmy at disease-associated sites correlates with impaired neurosensory and mobility function in older individuals.
- mtDNA heteroplasmy is proposed as a novel, noninvasive biomarker for predicting age-related functional impairments.
More Related Videos
06:53Visualization of Mitochondrial Respiratory Function using Cytochrome C Oxidase / Succinate Dehydrogenase COX/SDH Double-labeling Histochemistry
Published on: November 23, 2011
07:24Genotyping Single Nucleotide Polymorphisms in the Mitochondrial Genome by Pyrosequencing
Published on: February 10, 2023
Related Concept Videos
02:59Animal Mitochondrial Genetics
01:37Mitochondria