Do humans have a 'sleep gene'?

Ever envy those lucky few who seem to do fine on just a few hours of sleep per night? A researcher at the University of Utah says preliminary testing shows some people have a "sleep gene" that allows them to function at optimum levels with less sleep.

Dr. Christopher Jones, a neurologist and director of the Sleep/Wake Center at the U., is one of the principle investigators for the study, which was published Thursday in the journal Science.

While most adults need about 71/2 hours of sleep each day, those in the study who were found to have a genetic variation dubbed DEC2 regularly functioned at optimum levels on only six hours of sleep.

The same type of genetic variation has been observed in mice and flies, he said, noting mice that were a part of the study were monitored for sleep and physical activity. Those with the variation slept less and were active for more hours each day than the mice without it.

Jones said researchers studied a family where a mother and daughter both went to sleep between 10 and 10:30 p.m., and began their day regularly between 4 and 4:30 a.m.

"They simply weren't sleeping as much. Surprisingly, instead of being tired all the time without the normal amount of sleep, they were just the opposite. They were relentless, they never stopped moving, and they always had things to do," he said.

Their other immediate and extended family members who were part of the study didn't have the DEC2 genetic mutation, and required a normal about of sleep to function well, he said. Researchers regularly report new findings on the necessity of adequate sleep to overall health.

"The mother in this family makes me feel tired when she describes here activities for every day. She always has a trip to a foreign country planned, she has rheumatism but still goes dancing three nights a week.

"She just got back from a 50-day cruise where she danced every night. She plays bridge every night with friends," he said.

While Jones sees and diagnoses various sleep disorders on a regular basis, he's usually dealing with people who can't get enough sleep for one reason or another.

"It's interesting to have a short sleeper who is really energetic. Some of the famous people in history like Winston Churchill and Thomas Edison accomplished a lot but didn't sleep very much," he said. In fact, both men prided themselves on their ability to function with only four to five hours of sleep, and considered those who required more to be lazy.

At this point, it's not known how prevalent or rare genetic mutation is in humans, and Jones said researchers counted themselves fortunate to find the mother and her family, since she volunteered to be studied without any recruiting on their part.