Gene regulates length of sleep

Gene regulates length of sleep

Gene regulates length of sleep_Scientists on Thursday reported the discovery of the first human gene linked to regulation of how much time we sleep.

Writing in the journal Science, Ying-Hui Fu, University of California, San Francisco, professor of neurology, and colleagues reported the identification of a gene that regulates how much sleep one needs.

The discovery explains why some people can thrive on six hours of sleep a day rather than the recommended eight to eight-and-a-half hours.

"Short term and chronic disruptions in the length of optimal sleep can have serious consequences on cognition, mood and physical health, including cancer and endocrine function," said Fu.

Researchers studied a small extended family in which a mother and her daughter had life-long shorter daily sleep requirements than most individuals.

During blood tests of the mother and daughter, researchers said they discovered a mutation on their DEC2 gene which is considered to be rare. The DEC2 gene has been previously identified by scientists to be involved in the regulation of circadian rhythms.

The team then genetically engineered mice and fruit flies to have the mutated human gene. The mice tended to sleep less over the course of 24 hours and in electroencephalography (EEG) and electromyography (EMG) measurements indicating reduced nonREM and REM sleep, said Ying He, a postdoctoral fellow in the Fu lab.

The team also compared the responses of the genetically engineered mice to normal mice on six hours of sleep deprivation. They noted that the mice engineered with the mutated gene needed less time to compensate for lost sleep than normal mice.

"These changes in sleep homeostasis in the mutant mice could provide an explanation for why human subjects with the mutation are able to live unaffected by shorter amounts of sleep throughout their lives," said Fu.

In 2001 the UCSF identified a rare mutated gene that put some family members on an unusual sleep cycle. People with the condition, known as "familial advanced sleep phase syndrome", tend to fall asleep around 7:30 p.m. and wake up around 3:30 a.m.

Source: redorbit