We all know what it’s like to stay up too late on a school night. You start a new episode of Big Little Lies even though you have to be awake in seven hours, but tell yourself that you’ll only watch the first five minutes. Next thing you know it’s 3 a.m. and you’re sitting in the middle of your floor re-organizing your clothes because you feel like Laura Dern would disapprove of your closet. Well, as it turns out, that tendency to be a night owl might actually be genetic — concerns about Dern's taste in your wardrobe aside.
For some, staying up late is more than just the occasional ill-timed HBO binge. For people who suffer from Delayed Phase Sleep Disorder (DPSD), getting to sleep in time to wake up early in the morning can be a real challenge. DPSD disrupts a person’s circadian clock — the internal rhythm that tells us when to eat, sleep, and eat — causing it to run behind. This means their bodies are programmed to stay up and sleep in later than others. According to a new study published in the journal Cell last week, the disordered sleep schedules of individuals with DPSD may be the result of a gene mutation.
In the study, researchers looked at 70 people from six families, and found that among those who suffered from DPSD, many had a mutation in the gene known as CRY1. The mutation was not present in those without the disorder.
“Carriers of the mutation have longer days than the planet gives them, so they are essentially playing catch-up for their entire lives,” saya Alina Patke, the lead author of the study and a research associate at the Laboratory of Genetics at the Rockefeller University.
Patke and her team first identified the gene mutation seven years ago, in a 46 year-old woman who came in to their sleep clinic for help. They analyzed her natural sleep pattern by observing her in an apartment without any windows, TV, or internet, or as I would call it it “a waking nightmare”.
Without any traditional time cues, the woman settled into a regular pattern that was about an hour longer than the typical 24-hour circadian cycle, and when they sequenced the patient’s genes, they found a single-point mutation of her CRY1 gene, which means that only one “letter” of the gene sequence is off. Further study of six families in Turkey found that those carrying the mutated CRY1 gene had a clearly late-shifted sleep schedule.
Patke hopes that identifying the gene will help scientists understand the role it plays in determining a person’s circadian rhythm, and eventually allow them to develop treatments for disordered sleep conditions such as DPSD or jet-lag.
While being a night owl may not sound like a big deal, studies have linked staying up late with a host of medical problems, including Type 2 diabetes and metabolic syndrome, a set of symptoms that includes high blood pressure, high blood sugar, and potentially even heart disease.
Just because you have the CRY1 mutation doesn't mean you're doomed to a life of exhaustion. Patke says that practicing good sleep hygiene, like going to sleep at the same time every night, and avoiding bright screens before bed, can help you regulate your sleep pattern.