The scientists have discovered the few ultra-rare mutations occurring at birth and reducing person’s life. According to researchers, each of these DNA variants can shorten life expectancy by 6 months. Various combinations of these mutations can even dictate how long a person lives without the development of age-related diseases such as cancer, diabetes and dementia.
Human genes do not determine a specific natural life expectancy alone; diet and many other factors also play a large role. However, the studies have proven that DNA variants can affect the aging process. The biologists associate less than a third of this influence with the genes we inherit. Another source for age-related DNA changes is environment: solar radiation, exposure to chemicals, poor ecology, and other factors that create thousands of random mutations. Each person has different sets of these mutations, and most of them have little effect on life expectancy.
The search of such rare mutations occurring with a chance of 1 in 10,000 people required a group effort. The Harvard University geneticist Vadim Gladyshev, co-author of the new study, collaborated with fellow scientists and the biotechnology company Gero LLC in studying the British biobank, a public database, containing the genotypes of some 500,000 volunteers.
By working with more than 40,000 of these genotypes, the team looked for correlations between small changes in DNA and health status, conducting a so-called genome-wide associative study. For example, some of mutations that the work was aimed at completely knocked out genes, depriving all cells in the body of certain proteins.
It turns out that in average each person is born with six “best” variants of mutations that can reduce life expectancy and the time after which the development of serious diseases begins. The team spoke about this in the eLife magazine. The more mutations, the greater the probability that a person will develop an age-related disease at a younger age or that death will simply occur. “The exact combination of different mutations matters,” explains Gladyshev. In general, each mutation reduces life expectancy by 6 months, and the duration of a "healthy" life - by 2 months.
However, there are many white spots in the study. In the future, the scientists are planning to expand the selection of genomes, as well as study the genes of long-livers who are fortunate enough to live up to 100 years or more.
Source: https://www.popmech.ru/science/news-574374-redkie-mutacii-mogut-otnimat-gody-vashey-zhizni/
Photos are from open sources.
