Scientists have apparently discovered a "death gene" which pinpoints the hour a person is most likely to die.

The common variation also determines what time a person gets up in the morning.

Researchers at Beth-Israel Deaconess Medical Centre in the USA found the gene variation by accident.

They were originally researching the development of Parkinson"s and Alzheimer"s disease.

Internal biological clock

It is believed the findings could help with scheduling shift work and planning medical treatments.

They looked at the sleeping patterns of 1,200 65-year-olds.

Andrew Lim is one of the authors of the report and assistant professor in the division of neurology at the University of Toronto.

"The internal "biological clock" regulates many aspects of human biology and behaviour, such as preferred sleep times, times of peak cognitive performance, and the timing of many physiological processes. It also influences the timing of acute medical events like stroke and heart attack" he said.

"Previous work in twins and families had suggested that the lateness or earliness of one"s clock may be inherited and animal experiments had suggested that the lateness or earliness of the biological clock may be influenced by specific genes" he added.