London - Those who claim, as Margaret Thatcher and Winston Churchill did, to need less than five hours’ sleep are met with disbelief by the rest of us.
But short-sleepers like the two former British prime ministers really do exist, and the evidence is they have a gene mutation.
While most of us need around eight hours’ sleep a night, feeling foggy and confused if we don’t get it, "natural short-sleepers" feel well rested after only four to six hours.
Researchers at University of California, San Francisco, found more than 50 families with members who require less than six and a half hours of sleep.
Taking one of these families, they isolated a mutation of the ADRB1 gene, which increased the activity of brain cells that promote wakefulness.