Are you a night owl? This may be the reason why

  • Are you a night owl? This may be the reason why

Are you a night owl? This may be the reason why

Researchers argue that a certain gene mutations can transform people into night owls.

According to researchers at The Rockefeller University, there's a variant of a gene called CRY1 that slows the internal biological clock (also known as the circadian clock) - which normally is what tells the body when to feel exhausted at night and when you're ready to wake. For all of them, the circadian cycles were affected.

Professor Michael Young, who led the USA team from The Rockefeller University that made the discovery, said: "Compared to other mutations that have been linked to sleep disorders in just single families worldwide, this is a fairly impactful genetic change".

Researchers have found a genetic mutation that turns people into Martians - at least when it comes to sleep patterns.

Sleep or wakefulness disorder - ranging from insomnia to narcolepsy - can predispose people to chronic diseases including diabetes, obesity and depression.

True night owls are people who, even in the absence of smartphones and electrical lights, will still fall asleep and wake up late. "In the morning, they are not ready for the next day to arrive".

"Here, we report a hereditary form of DSPD associated with a dominant coding variation in the core circadian clock gene CRY1, which creates a transcriptional inhibitor with enhanced affinity for circadian activator proteins Clock and Bmal1", wrote the article's authors.

Researchers also collected skin cells from each person.

In this isolation, the woman settled into a rhythm that stretched about 1 hour longer than the typical 24-hour circadian cycle, and her sleep was fragmented, Patke said. However, a DSPD subject that caught the researcher's interest not only stayed up late, but had a cycle that was about 30 minutes longer. The 24-hour circadian clock aligns the internal physiology of organisms with the environment, but people with DSPD experience a delayed onset of sleep.

"Melatonin levels start to rise around 9 or 10 at night in most people", noted Young. "In this DSPD patient that doesn't happen until 2 or 3 in the morning".

The findings showed that a mutation in a gene called CRY1 alters the human circadian clock, which dictates rhythmic behaviour such as sleep/wake cycles.

In the study, published in Cell, researchers collaborated with sleep researchers at Weill Cornell Medical College where participants spent two weeks in a lab apartment isolated from all cues of time of day, so they could eat and sleep whenever they felt inclined.

The study found that among the families studied, 39 carried the CRY1 mutation and 31 did not.

Then, Young's team turned to large genetic databases from around the world to determine the prevalence of CRY1 mutations. They contacted researchers from Bilkent University in Ankara, Turkey, and in a conjoint effort they tracked down the people from the database and conducted interviews with members of six families as well as DNA sequencing tests. What was found was that they had delayed sleep phase disorder (DSPD).

She added that if in the future a drug is developed to help night owls align their sleep schedules to regular schedules, a similar drug could be used to help travelers deal with jet lag.

For now, many DSPD patients are able to control their sleep cycles-and get to bed earlier than their body wants-by following strict schedules.

Future studies are planned to work out whether CRY1 mutations also affect the metabolic cycles of people with DSPD, since the human circadian cycle is known to not only regulate but also hunger and levels of metabolites and hormones.