New marker
Scientists have found a biomarker of life expectancy
American scientists have found out that by the rate of accumulation of genetic mutations, it is possible to predict how many years a person will live. In women, this method also allows you to predict the period of fertility. The results of the study are published in the journal Scientific Reports (Cawthon et al., Germline mutation rates in young adults predict longevity and reproductive lifespan).
It has long been known that DNA damage occurs constantly throughout life, but the body has recovery mechanisms that prevent the accumulation of harmful mutations. Over time, these mechanisms become less effective, so, for example, elderly parents, as a rule, transmit more genetic mutations to their offspring through the germ line – egg and sperm.
Biologists from the University Utah and the University of Louisville have suggested that the rate at which a person acquires DNA mutations can serve as a biomarker of aging and it can be used to predict life expectancy even in young people, as well as fertility in women.
The basis for the study was the data bank of the Center for the Study of Human Polymorphism, an international research genetic institute in Paris, which plays a key role in many major studies contributing to the modern understanding of human genetics.
The sample included 41 families, each of three generations. The authors analyzed blood DNA sequences in triplets from 61 pairs of grandparents from the first generation and one of their children.
So, they compared the mutations found in the DNA of representatives of both generations, and were able to determine how many of them each parent had accumulated in an egg or sperm at the time of conception of the child, and then calculated the number of mutations and the rate of their accumulation for the second generation.
Since this study is retrospective, scientists had the opportunity to compare life expectancy with the number of accumulated mutations not only for the older, but also for the middle generation.
It turned out that young people who received fewer mutations from their parents and accumulated them at a lower rate during their lifetime lived about five years longer than those with a higher mutation growth rate. This difference is comparable to the effects of smoking or lack of physical activity.
"Thus, compared to a 32-year-old man with 75 mutations, we expect that a 40–year-old man with the same number of mutations will age more slowly and live longer," the University of Utah press release quotes one of the leaders of the study, professor of human genetics, Dr. Richard Cawthon.
"If the results are confirmed by other independent studies, it will have enormous consequences," says the second leader, Dr. Lynn Jorde. "It means we could find ways to fix ourselves and live longer."
Scientists have also found that the rate of accumulation of mutations increases during or shortly after puberty – this suggests that the aging of the body begins already in adolescence.
The authors also note the relationship between the rate of accumulation of mutations and fertility in women. Women with the highest rates of mutations had significantly fewer live births and stopped giving birth at a young age.
"Being able to determine when aging begins, how long women can remain fertile and how long people can live is an amazing opportunity," Dr. Kauton emphasizes. "If we can understand how developmental biology affects the frequency of mutations during puberty, we can develop medical interventions to restore DNA repair and other homeostatic mechanisms to the pre-puberty state."
The authors note that this is the first study of its kind, and hope that the results will help develop measures to combat aging.
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