Researchers from the Leiden University Medical Center have identified a rare genetic variant that may be associated not only with a longer lifespan but also with maintaining good health for a longer period of life, according to News Medical and Live Science.

Scientists are increasingly interested not only in lifespan but also in healthspan—the period during which a person remains active and free from serious chronic diseases.

Longevity is known to run in families. People from long-lived families tend to develop cardiovascular disease, diabetes, and other age-related conditions later in life. However, the specific genes responsible for this effect remain poorly understood.

Unlike most previous studies, the researchers focused not on individual long-lived people but on entire families in which many relatives had lived exceptionally long lives.

Earlier, the same research group showed that children of long-lived individuals develop cardiovascular and metabolic diseases approximately 13 years later, on average, than people of the same age from the general population.

In the new study, scientists analyzed the genomes of more than 200 long-lived families. They narrowed their search from tens of thousands of genes to several hundred promising candidates. Ultimately, they identified 12 rare genetic variants that may be associated with longevity.

One gene in particular attracted their attention: CGAS.

This gene plays a key role in the immune system. It helps the body detect viral infections and cellular damage, triggering an inflammatory response.

However, inflammation is a double-edged sword. Too little inflammation can leave the body vulnerable to infections, while excessive inflammation can damage tissues and accelerate aging.

The researchers found that in some members of long-lived families, one copy of the CGAS gene was less active than usual. They believe this may have resulted in a more balanced inflammatory response—strong enough to protect the body, yet not so intense that it causes unnecessary damage.

Such a balance may help people remain healthy longer and reduce the risk of age-related diseases.

What particularly intrigued the scientists was that the effect of this genetic variant appeared to be quite pronounced in laboratory experiments.

The next stage of the research will involve studies in living organisms. To do this, the scientists plan to use African killifish, small fish that are among the shortest-lived vertebrates on Earth. Their lifespan ranges from just three to nine months, making them an ideal model for studying the biology of aging.

The researchers intend to introduce the newly identified mutation into the fishes’ genome and examine whether it affects lifespan and the condition of various tissues throughout the body.

The authors emphasize that it is still far too early to speak of a “longevity gene.” Nevertheless, the findings provide valuable insight into the mechanisms of aging and could eventually contribute to the development of new strategies for preventing age-related diseases.