23andMe Genome-Wide Association Study on Human propensity to Get up early or Sleep in the Morning

February 2, 2016 by 2012pharmaceutical

23andMe Genome-Wide Association Study on Human propensity to Get up early or Sleep in the Morning

Reporter: Aviva Lev-Ari, PhD, RN

Women, they noted, were more likely to be morning people than men, and preference for the morning increased with age. Further, morning people were less likely to report insomnia, needing more than eight hours of sleep a night, or restless leg syndrome. They also have a lower prevalence of depression and of being underweight or obese.

Seven loci near established circadian rhythm genes to morningness
the odds of a morning person suffering from insomnia is 55 percent that of night owls, and
the odds of morning person having sleep apnea is 64 percent that of night people.However, they were unable to find clear genetic associations with related sleep phenotypes like insomnia, sleep apnea, and sleeping soundly. The researchers suggested that these phenotypes might be heterogeneous, influenced by environmental factors, or more subject to self-reporting bias.
no evidence that being a morning person was protective of depression or high BMI.
a variant of the BMI-linked FTO gene has some evidence for association with morningness,

Original Study

NATURE COMMUNICATIONS | ARTICLE OPEN

GWAS of 89,283 individuals identifies genetic variants associated with self-reporting of being a morning person

Abstract

Circadian rhythms are a nearly universal feature of living organisms and affect almost every biological process. Our innate preference for mornings or evenings is determined by the phase of our circadian rhythms. We conduct a genome-wide association analysis of self-reported morningness, followed by analyses of biological pathways and related phenotypes. We identify 15 significantly associated loci, including seven near established circadian genes (rs12736689 nearRGS16, P=7.0 × 10⁻¹⁸; rs9479402 near VIP, P=3.9 × 10⁻¹¹; rs55694368 near PER2, P=2.6 × 10⁻⁹; rs35833281 near HCRTR2, P=3.7 × 10⁻⁹; rs11545787 near RASD1, P=1.4 × 10⁻⁸; rs11121022 near PER3, P=2.0 × 10⁻⁸; rs9565309 near FBXL3, P=3.5 × 10⁻⁸. Circadian and phototransduction pathways are enriched in our results. Morningness is associated with insomnia and other sleep phenotypes; and is associated with body mass index and depression but we did not find evidence for a causal relationship in our Mendelian randomization analysis. Our findings reinforce current understanding of circadian biology and will guide future studies.