[dropcap]N[/dropcap]EW YORK – Whether we prefer to get up at the crack of dawn or work late into the night may be influenced by genes connected to the circadian rhythm, a study suggests.
U.S. researchers compared the genomes of nearly 90,000 individuals with their responses to the question of whether they defined themselves as a morning person or evening person an approach known as a genome-wide association study.
In a paper published today in Nature Communications, the researchers from consumer genetics company 23 and Me and San Jose State University report the discovery of 15 gene regions linked to our preference for or against “morningness.”
Seven of these gene regions are located near well-known genes that govern our body clock, or circadian rhythm, which is largely driven by exposure to light, with at least one associated with the relay of information about light to the brain.
Researcher and statistical geneticist Dr David Hinds said another of the genes linked to our preference for mornings or evenings was close to a gene associated with restless legs syndrome, a condition whereby people feel the need to constantly move their legs, particularly when in bed and trying to sleep.
Other genes identified in the study are linked to known sleep disorders, such as narcolepsy.
Hinds says these extreme sleep problems are easier to study because they are more readily classified, and the genes are easier to follow through the generations.