In 2009, Californian researchers met a woman who went to bed around midnight and woke at 4am feeling completely refreshed and alert. Apart from the short sleep duration, she displayed no other symptoms of insomnia.
Upon further study, researchers discovered the woman had a tiny mutation in the DEC2 gene. This mutation was also present in family members who had short sleep durations, but not in family members or volunteers who had 'normal' sleep durations.
Interestingly, researchers then bred mice with the same genetic mutation. The mice slept less than normal, but again appeared to be none the worse because of it. They remained alert and performed tasks just as well as regular mice.
It would appear that those with the DEC2 mutation are simply able to sleep more efficiently. In other words, the brains of these individuals are able to repair cellular damage, remove toxins, recharge energy supplies, consolidate memories and perform other 'housekeeping' tasks that happen during sleep more quickly than the rest of us.
This makes sense since we already know that sleep quality is far more important than sleep duration.
One common characteristic that researchers found among those with the DEC2 mutation was that they were typically very energetic and optimistic. They wanted to cram as much into their lives as possible. Researchers don't know whether this is related to the mutation, however.
So it turns out that if you're only getting a few hours of sleep each night but wake feeling refreshed and energized, it's unlikely that you have anything to be concerned about. You may just have a very efficient sleep system.
Last updated: July 27, 2015