Those who can get by on less than five hours of sleep have been found to carry a special gene, which experts believe negates the effects of sleep deprivation.

Ying-Hui Fu, a sleep researcher at University of California, says that those who carry the rare DEC2 gene appear to have a ‘resistance’ against the health risks which normally come with too little sleep.

“My lab uses human genetics to gain a better understanding on this topic,” she writes on Reddit. “We’ve found that sleep behaviour is heavily influenced by our genetic makeup.”

“Just like many other traits - height, weight, body shape - sleep behaviour is at least partly inherited. We discovered a mutation in the DEC2 gene that allows some people to sleep only four to six hours a night and feel completely refreshed.”

Though getting too little sleep is thought to heighten the risk of cardiovascular diseases and impaired brain function, Fu believes that the gene changes a person’s typical circadian rhythm – our natural body clock.

Getting to much sleep, in fact has the opposite effect on these people, who are left feeling groggy and out of sorts by the recommended eight hours.

Are you one of the ‘genetically advanced’ four-hours-a-night sleepers?