A Twin Study of Mitochondrial DNA Polymorphisms Shows that Heteroplasmy at Multiple Sites Is Associated with mtDNA Variant 16093 but Not with Zygosity
2011

Twin Study of Mitochondrial DNA Variants and Heteroplasmy

Sample size: 178 publication Evidence: moderate

Author Information

Author(s): Andrew Toby, Calloway Cassandra D., Stuart Sarah, Lee Sang Hoon, Gill Raj, Clement Gail, Chowienczyk Philip, Spector Tim D., Valdes Ana M.

Primary Institution: Department of Twin Research and Genetic Epidemiology, King's College London

Hypothesis

Is heteroplasmy in mitochondrial DNA associated with age, BMI, and insulin levels in women?

Conclusion

The study found that mitochondrial DNA heteroplasmy is weakly correlated with age but more consistently associated with BMI.

Supporting Evidence

  • The overall estimated prevalence of heteroplasmy was 17%.
  • Heteroplasmy was higher in older subjects (23% vs 10%).
  • Concordance rates for heteroplasmy were 94% for dizygotic and 100% for monozygotic twins.
  • Heteroplasmy at position 16093 was found in buccal swabs but not in blood samples.

Takeaway

This study looked at DNA from twins to see if certain changes in DNA are linked to age and weight. They found that older people had more changes, but being heavier was more closely linked to these changes.

Methodology

The study analyzed mitochondrial DNA from buccal swabs and blood samples of 178 women, focusing on heteroplasmy prevalence and its association with age, BMI, and insulin levels.

Limitations

The sample size is relatively small and findings are subject to replication.

Participant Demographics

178 female Caucasian twins, mean age 57.5 years.

Statistical Information

P-Value

p<0.03

Statistical Significance

p<0.03

Digital Object Identifier (DOI)

10.1371/journal.pone.0022332

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