A genetic mutation identified as early as 2017 and occurring with surprising frequency upsets the biological clock, triggering the so-called delayed sleep phase disorder. People with this disorder cannot fall asleep until late at night (often after two in the morning).
If people have problems falling asleep in the evening and are usually awake late into the night, this could be due to a genetic mutation. This is suggested by the results of a study involving researchers from the University of California – Santa Cruz. The study was published in the English language journal “Proceedings of the National Academy of Sciences”.
A genetic mutation leads to a so-called delayed sleep phase disorder in humans. This means that people cannot fall asleep until late at night. As a result of the disturbed sleep, affected persons suffer from difficulties getting up the next day, for example, and reduced performance.
Can sleep problems be explained by mutation?
According to the research group, most of the genetic mutations that are known to alter the internal clock occur very rarely; for example, they affect only one person in a million. However, the genetic variant identified in the 2017 study was found in about one in 75 people of European descent.
The results of the current study reveal the molecular mechanisms involved and point the way to possible treatments, the researchers report. The mutation has dramatic effects on human sleep behavior, so it is very encouraging that a concrete mechanism has been identified in the biological clock that combines the biochemistry of a protein with the control of human sleep behavior, the researchers report in a press release.
The daily cycles in practically every aspect of human physiology are driven by cyclic interactions of so-called clock proteins in the cells. Genetic variations that alter the clock proteins can alter the timing of the internal clock and thus cause sleep phase disorders. A shortened cycle causes people to fall asleep and wake up earlier than normal, while a longer cycle causes people to stay up longer and sleep longer.
Mutation occurs surprisingly frequently
People stay awake for a long time for many different reasons and disorders can be difficult to diagnose. Therefore, the discovery of a relatively common genetic variation associated with sleep phase disorders was of great interest to the research group. The understanding of the underlying process needs to be further improved, but this one mutation is clearly an important cause of late night behavior in humans, the researchers add.
The mutation mentioned above concerns a protein called cryptochrome, one of the four most important watch proteins. Two of the clock proteins (CLOCK and BMAL1) form a complex that turns on the genes for the other two (period and cryptochrome), which then join together to suppress the activity of the first pair so that they switch themselves off and start the cycle again.
We are currently investigating ways to develop therapeutics that could help people with delayed sleep phase disorders. (as)
A study published earlier this year showed how certain genetic mutations can shorten the time of the internal clock by affecting a molecular switching mechanism that causes some people to fall asleep early in the evening and wake up early in the morning.
This feedback loop is the central mechanism of the biological clock that controls the daily variations in gene activity and protein levels throughout the body. The cryptochrome mutation causes the close binding of cryptochrome to the CLOCK:BMAL1 complex to change, affecting the internal clock in such a way that people can only fall asleep late.
WashingtonNewsday Health and Wellness.