Counting DNA mutations predicts lifespan, raises hopes of reversing aging
New research from the University of Utah Health, published in the journal Scientific Reports, is offering the fascinating suggestion that a person’s lifespan could be predicted at a young age by measuring the volume of genetic mutations they accumulate. The research suggests this information may be used in the future to identify young adults most at risk of late-life medical problems so early preventative interventions can be deployed.
”If the results from this small study are validated by other independent research, it would have tremendous implications," says Lynn Jorde, co-author on the study. "It would mean that we could possibly find ways to fix ourselves and live longer and better lives."
The study hypothesized rates of accumulating genetic mutations in young adults could predict not only general lifespan but fertility span in women. To investigate this hypothesis the researchers sequenced DNA from over 120 grandparents spanning 41 families. Without a DNA sample from decades ago to compare, the researchers looked to their children’s DNA to get a picture of each older subject at a younger age.
Germline mutations are genetic mutations passed on from parent to child. By measuring which germline mutations were passed on to the subsequent generation the researchers were able to calculate how many genetic mutations the grandparents had accumulated at the time they conceived their children. This then allowed the researchers to compare each person’s rate of accumulated genetic mutations to their overall lifespan.
The results suggest those young adults with a slow rate of accumulated genetic mutations could on average live around five years longer than someone at the same age with a much higher rate of genetic mutations. Richard Cawthorn, lead author on the study, says this lifespan difference is comparable to what epidemiologists see in subjects with deleterious habits such as smoking.
"So, compared to a 32-year-old man with 75 mutations, we would expect a 40-year-old with the same number of mutations to be aging more slowly," explains Cawthon. "We'd expect him to die at an older age than the age at which the 32-year-old dies."
Higher mutation rates at young ages also correlated with less live births in women. This suggests the metric can also be linked with fertility.
The study of course has its limitations. Due to the nature of the research only germline mutations were directly studied. Somatic mutations, genetic changes not inherited from a parent or passed to offspring, were not explicitly tracked in the study. The researchers do, however, hypothesize a distinct correlation between germline mutation accumulation rates and somatic mutation accumulation rates over a person’s life.
"If we can get to a point where we better understand what sort of developmental biology affecting mutation rates is happening during puberty, then we should be able to develop medical interventions to restore DNA repair and other homeostatic mechanisms back to what they were before puberty,” concludes Cawthorn. “If we could do that, it's possible people could live and stay healthy much longer."
The new study was published in the journal Scientific Reports.
Source: University of Utah Health