Mutation causes people to go to bed late
Are you one of those people who stay up late at night and have trouble getting up the next morning? If so, this could be due to a mutation in their genes. Researchers have now found that the tendency to go to bed late may be related to their genes.
The scientists at the Laboratory of Genetics at Rockefeller University discovered in their investigation that it could be in our genes whether we are so-called night owls and always go to bed late at night. The doctors published the results of their study in the medical journal "Cell".
CRY1 mutation found in people with delayed sleep disorders
For their current study, the researchers examined 70 people from six different families. They found that mutation in a gene called CRY1 was found in subjects who suffer from a so-called delayed sleep phase disorder (DSPD).
At DSPD, people go to bed late and get up later in the morning
In those affected, the so-called circadian clock is set backwards, so these people wake up later in the morning and go to bed later in the evening. However, the mutation was missing among the members of the same families who did not suffer from DSPD, the researchers explain. Laboratory experiments have also shown that this gene could play a key role in the circadian clock.
Effects affect all of life
This is the first genetic mutation that has been associated with DSPD, the scientists say. People with this mutation go to bed late every day, so the mutation has a significant impact on the lives of those affected, explains author Alina Patke from Rockefeller University.
Almost all life in the world is influenced by the circadian rhythm
The so-called circadian clock is an internal rhythm that influences almost all life on earth. In humans, the rhythm determines when those affected are tired, hungry or awake. It even regulates body temperature, the doctors add.
In many professions, such a mutation is a disadvantage
For certain professions, DSPD certainly does not lead to any significant disadvantages. Bartenders could even benefit from such a delayed sleep cycle, for example. Surgeons and other normal jobs that require people to get up early in the morning are at a disadvantage, however, due to the mutation associated with DSPD.
First case of DSPD
For the first time, a mutation associated with DSPD was detected seven years ago in a 46-year-old woman in the United States. This was due to their severe sleep problems for an examination in a sleep laboratory, explain the doctors.
Sufferers should live shielded on their own schedule for two weeks
The researchers then analyzed the woman's natural sleep patterns by shielding herself from all environmental influences in an apartment for two weeks. There were no windows, no television and no Internet, explains the author Patke. The participant should live there on her own schedule. During this isolation, the woman began 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 Patke team 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 patterns.
Further investigations were carried out in Turkey
Using a database of genomic information for people in Turkey, the researchers identified people who carried the CRY1 mutation. The scientists sought out these people and conducted talks and further DNA sequencing among members of six families.
The center of sleep is shifted backwards in people with CRY1
Among the Turkish family members, 39 people carried the CRY1 mutation. 31 people did not have this mutation. The sleep cycles of family members with the gene were significantly shifted back, the scientists say. Her focus of sleep fell between 6 a.m. and 8 a.m. The focus of sleep for people without the mutation was around 4 a.m., the experts add.
Not every night owl suffers from a CRY1 mutation
Around ten percent of the population suffer from a delayed sleep phase disorder. But not all night owls carry the mutation. Of course, there are also people who regularly go to bed late, but still do not suffer from the effects of a CRY1 mutation. Other causes of DSPD can probably also be at the root, explains Patke.
Are there strategies to reset the internal clock?
However, identifying at least one genetic mutation as the cause of the sleep disorder is an important step. Understanding how these rhythms are controlled can help manipulate the mutation with medication, the doctors say. In the meantime, until such medications are available, people with sleep disorders can use other strategies to reset their internal clocks. Sufferers should go to bed at a specific time each evening (including weekends) and get up at a specific time each morning. They should also avoid bright lights in the sleeping environment (including laptops and smartphones), the expert advises. (as)