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

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 near RGS16, P = 7.0 x 10(-18); rs9479402 near VIP, P = 3.9 x 10(-11); rs55694368 near PER2, P = 2.6 x 10(-9); rs35833281 near HCRTR2, P = 3.7 x 10(-9); rs11545787 near RASD1, P = 1.4 x 10(-8); rs11121022 near PER3, P = 2.0 x 10(-8); rs9565309 near FBXL3, P = 3.5 x 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.