A SINGLE gene that could explain why some people can get by on just a few hours’ sleep each night has been discovered.
A small mutation in a gene known as Shaker — also nicknamed the “Thatcher gene” after the former Prime Minister, who famously needed little sleep — allows fruit flies to thrive on a fraction of the sleep that they usually require, according to research in the United States.

http://www.timesonline.co.uk/article/0,,2-1588776,00.html