LIFE> Health
Sound sleep is natural
(China Daily/Agencies)
Updated: 2009-08-19 18:03

Scientists have discovered a gene that helps a mother and daughter stay alert on about six hours sleep a night, two hours less than the rest of their family needs.

It's believed to be a very rare mutation, not an excuse for the rest of us who stay up too late. But the finding offers a new lead to study how sleep affects health.

The National Institutes of Health says adults need seven hours to nine hours of sleep for good health. Regularly getting too little increases the risk of health problems, including memory impairment and a weakened immune system.

University of California, San Francisco, researchers have found a gene involved in regulating length of sleep. The gene named DEC2 is involved in regulation of circadian rhythms, the body's clock.