There’s always someone that seems to need much less sleep than others, an early riser perhaps, full of energy and remarkably unaffected, even with fewer hours of shuteye. This may all be thanks to their ‘short sleep’ gene. In 2009, a groundbreaking study led by Ying-Hui Fu PhD, Professor of Neurology, led to the discovery of a ‘short’ sleep gene – a gene where individuals naturally sleep less than 6 hours, yet still function normally and feel rested. A decade later, Fu’s team discovered a second ‘short sleep’ gene and there have been further short sleep genes discovered since. So how is genetics connected to our sleeping pattern and how can we spot whether we belong to this tribe of short sleepers?
Mutated ‘short sleep’ genes identified
In the landmark study looking at genetics and sleep, the short sleep gene was first identified as a rare mutation of the DEC2 gene. This gene plays a part in regulating the body’s circadian rhythm. The mutation was named the short gene as it allowed a shorter sleep for the individual, yet with none of the drawbacks associated with sleep deprivation.
Studying another family of natural short sleepers, researchers discovered another mutation that affects a gene called ADRB1 which can alter the neurotransmitters in the human brain. Essentially allowing the individual shorter sleep time, but more importantly still content despite less sleep. Since then a third short sleep gene has been discovered. The natural ‘short gene’ sleepers are sometimes also referred to as ‘micro-sleepers´.
A generation of ‘short sleep’ genes
The study which led to the discovery of the second ‘short sleep’ gene, the rare mutation in the ADRB1 gene, also found that it was being passed through several generations of one family. None of whom had the initial DEC2 mutation. The family members who inherited one copy of the mutant gene all had a shortened sleep cycle. They had adrenergic receptors which respond to hormones, including those that regulate the sleep/wake cycle. Some of the family members who had the mutated gene would testify to having around 5 hours of sleep and then waking up, ready to go, but always refreshed and alert, without that groggy feeling. The same was true of their father and in turn their children. With the mutated sleep genes, genetics matters!
The sweet ‘short sleep’ spot
Being a natural short sleeper with a specific ‘short sleep’ gene is not to be confused with general short sleepers, who may also sleep less than 6 hours a night, but who often can suffer from mild to severe sleep deprivation as a consequence and are at risk of diseases ranging from obesity, coronary heart disease, diabetes and more. Natural short sleepers on the other hand tend to benefit from their biological condition. Fu elaborates: “Natural short sleepers experience better quality and sleep efficiency.” Research has found they tend to be more optimistic, more energetic and better multitaskers. Further research suggests that they can often be ‘Type A’ personalities, extremely driven and generally be both psychologically and physically strong and active.
The importance of sleep research & genetics
The powerful impact of sleep research on genetics is that it opens up a world of possibilities for sleep disorder treatments. Dr. Louis Ptáček, the senior author on the sleep study which discovered the second short gene explains: “When we mapped and cloned this gene, it was quite exciting because this was the first direct proof that this gene and this receptor are directly involved in sleep homeostasis, or sleep regulation. If we could develop compounds that help people to sleep better, and to sleep more efficiently, we believe that it could have profound consequences for improving human health in general.”
Dr. Jesse Mindel, a researcher specializing in sleep medicine summarizes it further: “The longer people stay awake, it affects their cognitive function, decision-making, their emotions, and their behaviors,” he said. “So if you could affect the homeostatic drive (sleep regulation), then you may not need as much sleep as you do currently.”
How likely is it that you have a ‘short sleep’ gene
If you hope to be among the lucky few that can get by on less sleep because of your genetic make-up, we’re sorry to disappoint. The ‘short sleep’ gene seems to be rare and Fu estimates the condition to only be prevalent in approximately three percent of people. If you suspect this still may be you, a clue could be to see whether others in your family tend to be early risers and manage on less sleep.
In the meantime, the fascinating research into short sleep genes will no doubt continue to uncover further genetic and hereditary conditions that impact sleep.
Interested in reading more about sleep science? Understanding the ‘why’ and the ‘how’ is essential in improving our sleep habits!