University of Pennsylvania researchers have tied a new variant in the BHLHE41 gene to some people's ability to get by on less sleep. Previous work from another group implicated a different variant in that gene to sleep deprivation.
As they report in the journal Sleep, UPenn's Allan Pack and his colleagues studied a cohort of twins that was exposed to acute sleep deprivation. The researchers also tested the participants' cognitive skills.
In one twin, the researchers uncovered a BHLHE41 gene variant, p.Tyr362His, that his brother lacked, and they noted that the brother with the gene variant normally slept about an hour less than his non-carrier brother. During sleep deprivation, the carrier twin had on average fewer lapses of performance on the cognitive skills test, suggesting to Pack and his colleagues that "the mutation was associated with resistance to the neurobehavioral effects of sleep deprivation."
The researchers also examined a cohort of unrelated people with chronic partial sleep deprivation, but the variant it identified there — p.Pro384Gln — didn't seem to influence sleep duration.
“This work provides an important second gene variant associated with sleep deprivation and for the first time shows the role of BHLHE41 in resistance to sleep deprivation in humans,” says first author Renata Pellegrino from the Children’s Hospital of Philadelphia in a statement. “The mutation was associated with resistance to the neurobehavioral effects of sleep deprivation.”
CBS News notes that that American Academy of Sleep Medicine recommends that adults sleep for seven to nine hours a night, though the Centers for Disease Control and Prevention says that more than a quarter of adults say they sleep for six hours or less a day.