Genes may decide whether you are an owl or lark

Los Angeles: Scientists have identified genetic variants associated with an individual's preference towards early rising, a finding that can uncover the genetics behind a variety of diseases and conditions. A new study identified 15 locations in DNA (loci) associated with 'morningness.'

Morningness is governed by differences in circadian rhythm, which have previously been linked to medically relevant traits such as sleep, obesity and depression, researchers said. The study of more than 89,000 people found that seven of the loci associated with morningness are near genes previously known to be involved in circadian rhythm.

The findings showed that the majority (56 per cent) of participants consider themselves night owls, while women and adults over age 60 are more likely to be morning people. Morning people were significantly less likely to have insomnia, or require more than eight hours of sleep per day, and less likely to suffer from depression than individuals who reported being 'night owls.'

Researchers also found that after taking into account the effect of age and sex, morning persons are likely to have lower Body Mass Index (BMI). Variants in the FTO gene associated with obesity were also found to be associated with being a morning person.