Do you get your best work done late at night and then struggle to wake up in the morning? New research suggests your night owl tendencies could be hard-wired in your genes.
In the new study, researchers looked at 70 people from six families and found that a mutation in a gene called CRY1 was common among those who have a condition known as delayed sleep phase disorder (DSPD). In people with this condition, the circadian clock runs behind, so they wake up later than normal, and go to bed later than normal.
The mutation was absent in the members of these same families who did not have DSPD, the researchers said. In addition, the researchers showed in lab experiments that this gene may play a key role in driving the circadian clock.
“Carriers of the mutation have longer days than the planet gives them, so they are essentially playing catch-up for their entire lives,” Alina Patke, the lead author of the study and a research associate in the Laboratory of Genetics at The Rockefeller University, said in a statement from Cell Press. The findings are published today (April 6) in the journal Cell.
The circadian clock is an internal rhythm that guides nearly all life on Earth. In people, it dictates when one feels tired, hungry or awake. It even regulates body temperature. Most people are hard-wired to a 24-hour clock, but up to 10 percent of peoplewith DSPD follow an internal clock that runs on a longer loop.
“A person like a bartender, for example, might not experience any problem with the delayed sleep cycle,” Patke told Live Science. “But someone like a surgeon who has to be in the OR in the early morning – that’s not compatible.”
Patke and her colleagues first identified the DSPD-linked mutation seven years ago, in a 46-year-old U.S. woman who had come to a sleep clinic after a long struggle with her late sleep cycle.