This gene mutation affects the sleep and the internal clock of night people

Mutation causes people to go to bed late
Are you one of those people who stay awake late at night and have trouble getting up the next morning? If so, this could be due to a mutation of their genes. Researchers now found that the tendency to go to bed late could be related to their genes.

The scientists from the Laboratory of Genetics at Rockefeller University found in their research that it could be in our genes whether we are so-called night owls and always go to bed late at night. The physicians published the results of their study in the medical journal "Cell".

Many people regularly go to bed late at night. In the morning, those affected often have problems getting up. Researchers found that mutating the genes could be to blame. (Image: Sven Vietense / fotolia.com)

CRY1 mutation detected in people with delayed sleep phase disorder
For their current study, the researchers studied 70 people from six different families. They found that mutation in a gene called CRY1 was found in subjects suffering from a so-called delayed sleep phase disorder (DSPD).

At DSPD people go to bed late and get up later in the morning
For sufferers, the so-called circadian clock is set backwards, so these people wake up in the morning later and go to bed later in the evening. However, the mutation was missing among members of the same families who did not suffer from DSPD, the researchers explain. In addition, it has been demonstrated in laboratory experiments that this gene could play a key role in the circadian clock.

Impacts affect the whole life
This is the first genetic mutation that has been associated with DSPD, say the scientists. People with this mutation go to bed late every day, so the mutation has a significant impact on their entire lives, says author Rockwell University's Alina Patke.

Almost all life in the world is influenced by the circadian rhythm
The so-called circadian clock is an internal rhythm that affects almost all life on earth. In humans, the rhythm determines when those affected are tired, hungry or awake. He even regulates the body temperature, add the physicians.

In many professions such a mutation is a disadvantage
For certain professions, DSPD certainly does not lead to significant disadvantages. For example, bartenders could benefit from such a delayed sleep cycle. However, surgeons and other normal occupations that require people to get up early in the morning are at a disadvantage because of the DSPD-associated mutation.

First case of DSPD
For the first time, a DSPD-associated mutation was detected seven years ago in a 46-year-old woman in the United States. This was due to their strong sleep problems to a study in a sleep laboratory, explain the doctors.

Concerned should live two weeks shielded on their own schedule
The researchers then analyzed the woman's natural sleep patterns by screening them for two weeks in a home away from any environmental impact. There were no windows, no TV and no internet, explains author Patke. The participant should live there on her own schedule. During this isolation, the woman entered a rhythm that lasted about 1 hour longer than the typical 24-hour circadian cycle. The woman's sleep was also fragmented.

CRY1 mutation is associated with delayed sleep phase disorder
When sequencing their genes, the researchers identified the CRY1 mutation. In the new study, the team from Patke confirmed the linkage of genetic CRY1 mutations to delayed sleep phase disorder. For this purpose, the mutation was sought in the adult family members of the woman and in other so-called population moths.

Further investigations in Turkey were carried out
Using a database of genomic information for people in Turkey, the researchers identified individuals with the mutation of CRY1. The scientists visited these people and conducted conversations and further DNA sequencing among the members of six families.

The center of sleep is shifted backwards in people with CRY1
Among the Turkish family members, 39 persons carried the CRY1 mutation. 31 people did not have this mutation. The sleep cycles of family members with the gene were significantly delayed, say the scientists. Her center of sleep fell between 6 o'clock and 8 o'clock. The midpoint of the sleep of people without the mutation was around 4 pm for comparison, the experts add.

Not every night owl suffers from a CRY1 mutation
About ten percent of the population suffer from a delayed sleep phase disorder. But not all night owls carry the mutation in themselves. Of course, there are also people who go to bed late, but still do not suffer from the effects of a CRY1 mutation. Probably other causes of the DSPD may also underlie, explains Patke.

Are there any strategies to reset the internal clock??
Nevertheless, the identification of at least one genetic mutation as the cause of the sleep disorder is an important step. Understanding the control of these rhythms can help manipulate the mutation with drugs, say the physicians. In the meantime, until such drugs exist, people with sleep phase disorder may employ other strategies to reset their internal clocks. Patients should go to bed at a certain time every evening (even on weekends) and wake up every morning at a certain time. In addition, they should avoid bright lights in the sleeping environment (including laptops and smartphones), advises the expert. (As)