The genetic variant is one of a handful that have been identified in people who don’t need a lot of sleep

May 04, 2025 | 08:00pm

Don’t need much sleep? Mutation linked to thriving with little rest

The genetic variant is one of a handful that have been identified in people who don’t need a lot of sleep

Some people can function well on little sleep.Credit: Oleg Breslavtsev/Getty

Most people need around eight hours of sleep each night to function, but a rare genetic condition allows some to thrive on as little as three hours. In a study published today in the Proceedings of the National Academy of Sciences¹, scientists identified a genetic mutation that probably contributes to some people’s limited sleep needs.

Understanding genetic changes in naturally short sleepers — people who sleep for three to six hours every night without negative effects — could help to develop treatments for sleep disorders, says co-author Ying-Hui Fu, a neuroscientist and geneticist at the University of California, San Francisco.

“Our bodies continue to work when we go to bed”, detoxifying themselves and repairing damage, she says. “These people, all these functions our bodies are doing while we are sleeping, they can just perform at a higher level than we can.”

In the 2000s, Fu and her colleagues were approached by people who slept six hours or less each night. After analysing the genomes of a mother and daughter, the team identified a rare mutation in a gene that helps to regulate humans’ circadian rhythm, the internal clock responsible for our sleep-wake cycle. The researchers suggested that this variation contributed to the duo’s short sleep needs. That discovery prompted others with similar sleeping habits to contact the laboratory for DNA testing.

The team now knows several hundred naturally short sleepers. Fu and her colleagues have so far identified five mutations in four genes that can contribute to the trait — although different families tend to have different mutations.