Genes may decide whether you are an 'owl' or 'lark': study

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, including HCRTR2 (linked to narcolepsy), FBXL3 (shown to have extended circadian period) and VIP (found to prolong REM sleep).

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.

"In this study we set out to discover more about an individual's preference towards early rising and were able to identify the genetic associations with "morningness" as well as ties to lifestyle patterns and other traits," said Youna Hu from 23andme, a biotechnology company in California, US.
"With the information we have, we can uncover the genetics behind a variety of conditions and diseases, and hopefully reach a better understanding of how we differ from one another," David Hinds, senior research scientist at 23andMe and a co-author of the paper added.
The findings were published in the journal Nature Communications.