“…The results of several Genome-Wide Association Studies (GWAS) on sleep duration, sleep latency, sleep depth, sleep quality, insomnia, daytime sleepiness, sleep apnea, and actigraphic measurements are available (Allebrandt et al, 2013; Amin et al, 2016; Byrne et al, 2013; Cade, Chen, et al, 2016; Cade, Gottlieb, et al, 2016; Gottlieb et al, 2015; Gottlieb et al, 2007; Lane et al, 2017; Marinelli et al, 2016; Ollila et al, 2014; Scheinfeldt et al, 2015; Spada et al, 2016), yet many of these phenotypes are independent of chronotype (Jones et al, 2016; Lane et al, 2017; Lehnkering & Siegmund, 2007). Two early GWAS identified several single nucleotide polymorphisms (SNPs) associated with the chronotype measure bedtime.…”