Doctors always say it: it is important to sleep 8 hours per night to be rested. But there are those with 3 or 4 hours per night are really well, and they don’t need to continue sleep. Now a research group led by the Chinese Academy of Sciences (China) has shown that there is a rare genetic mutation responsible for this anomaly
Eight hours of sleep They are always recommended by doctors, who repeat how they are very important for the rest of body and mind. But there are those with 3 or 4 hours a night is really fineand does not need to continue sleep. Now a research group led by Chinese Academy of Sciences (China), has shown that there is one rare genetic mutation responsible for this anomaly.
In particular, researchers have sought new mutations in the DNA of a person who sleeps little by nature, and have found one in Sik3a gene that codes for an enzyme (that is, that “orders” the cells to produce it) which, among other things, is active in the space between neurons.
A story that begins many years ago
In fact, for some time the “dogma of eight hours of sleep” has been put in crisis: sleep researchers have for example know that people in Japan have been sleeping much less than people in the United States, Canada and in most European countries.
And one study of 2024 led by University of Michigan (USA) also proposed that relationship between sleep and health duration is also moderate from one’s own beliefs and one’s own cultural background.
In the 2000s, the same research group that today announced the new discovery had been contacted by people who slept six hours or less per night and, after analyzing the genomes of a mother and daughter, the team had identified a rare mutation in a gene that helps to regulate the Upper human rhythmthe “internal watch” responsible for ours sleep-wake cycle.
The researchers, already at the time, had hypothesized that this variation contributed to the short need for sleep of the two. This discovery had therefore pushed other people with sleep habits similar to contacting the laboratory for a DNA test.
What scientists have now discovered
In this last study, the researchers have sought new mutations in the DNA of a person who sleeps little by nature, actually finding one in Sik3, a gene that codes for an enzyme that, among other things, is active in the space between neurons.
The discovery, among other things, comes after ananother of 2016 of a research group in Japan that had identified other mutation, always in Sik3, which could cause unusual sleepiness, confirming that that gene is actually decisive in the sleep-wake rhythm.
Our body continues to work when we go to bed, detoxifying and repairing the damage -explains Ying-Hui Fu, co-author of the work-These people simply have an extra capacity: they can simply perform all the functions that our body performs at a higher level while we sleep
The team now knows several hundred people who sleep little by natureand have identified in total five mutations in four genes Which can contribute to this trait, although different families tend to have different mutations.
One more discovery
But it does not end here: it is known, in fact, that the brain induces the deep sleep To heal from potentially lethal lesions. And now the team has also discovered that the mutant enzyme is more active in brain synapses.
This suggests that the mutation could reduce sleep by supporting thebrain homeostasisthat is, that process through which the brain maintains one state of internal equilibriumregulating vital parameters such as temperature, blood pressure, glucose level and other indispensable factors for survival.
Therefore the discovery is even more significant, because it supports the oldest theory according to which sleep helps to restore the brain.
Among other things, last January a research group led byUniversity of Copenhagen (Denmark) found that a molecule called norepinefrine plays a key role in cleaning the brain and that during deep sleep the brain trunk releases small waves of norepinefrine about once every 50 seconds.
The researchers also explained that this molecule triggers the contraction of blood vesselsgenerating slow pulsations that create a rhythmic flow in the surrounding fluid For take away the waste.
What happens now (and potential applications)
The researchers are still trying to understand how these genes and their variants can influence sleep in a more general way, and hope that the discovery of a sufficient number of mutations in subjects naturally with a short sleep can help the scientific community to get a more precise idea of how sleep is regulated in humans.
Understanding genetic changes in people who sleep naturally little, that is, people who sleep from three to six hours every night without negative effects, could help develop Treatments for sleep disorders
concludes Ying-Hui wasco -author of the research
The work was published on Proceedings of the National Academy of Sciences.
Sources: Nature News / Proceedings of the National Academy of Sciences
