Subjects: R and D
Scientists have identified a single-gene mutation that enables people to function effectively with far less sleep than most, a discovery that could lead to improved understanding of sleep cycles and open up new paths toward the treatment of insomnia and other sleep disorders.
Ying-Hui Fu and colleagues at UCSF made the find while conducting routine DNA screening on blood samples from people that had participated in several sleep studies.
The scientists had been searching for gene variations that affect circadian rhythms and other aspects of the sleep cycle. When they identified 2 specimens having unusual mutations of the so-called DEC2 gene, they traced them back and found a mother and daughter who routinely functioned on 6 hours of sleep per night. The average requirement is 8 to 8.5 hours per night.
The scientists then bred mice to have the same mutation, and found they required less sleep and recovered more easily from experimental sleep deprivation than regular mice.
The study “opens up a window to understanding the genetic basis of individual differences in sleep duration. You have a piece of the puzzle and you can begin trace back,” Charles Czeisler told the New York Times. He’s chief of sleep medicine at Brigham and Women’s Hospital.
The 2 women turn in around 10 or 10:30 each night and wake up ready to rock and roll at 4 or 4:30 in the morning, according to Fu.
Many people sleep for six or fewer hours per night, but have to use stimulants and alarm clocks to pull off the feat. “That’s a very different thing,” Fu told the Times. “Our body needs 8 to 8.5 hours.”
The mother and daughter were the only ones among 70 families found to have the handy mutation. In all likelihood, fewer than 5% of people are naturally short sleepers.
The write-up is in Science.