J Sleep Res. (2014) 23, 607–608
Editorial
Daily variations in sleep: associated genes and effects on affect GENOME-WIDE ASSOCIATION STUDY Interindividual variation in sleep duration is determined in part by genetic factors, and identification of the genes involved may help in understanding the mechanisms underlying sleep regulation, sleep function and the mechanisms by which extreme sleep durations associate with health and disease. Genome-wide association studies are one approach with which to identify these genes and this approach has been applied to various conditions and traits, but very few of these studies have been conducted for sleep. Genome-wide association studies require large sample sizes; for example, in a recent report on the determinants of human height the sample size was 253 288 (Wood et al., 2014), and in another study on type 2 diabetes in African Americans 8284 cases and 15 543 controls were included (Ng et al., 2014). These are challenging sample sizes. In the present issue of the Journal of Sleep Research Ollila et al. report the results from a genome-wide association study of sleep duration in the Finnish population (Ollila et al., 2014). The discovery sample comprised 1941 individuals living in Finland. No genomewide significant associations (which would require a P-value
Editorial
Daily variations in sleep: associated genes and effects on affect GENOME-WIDE ASSOCIATION STUDY Interindividual variation in sleep duration is determined in part by genetic factors, and identification of the genes involved may help in understanding the mechanisms underlying sleep regulation, sleep function and the mechanisms by which extreme sleep durations associate with health and disease. Genome-wide association studies are one approach with which to identify these genes and this approach has been applied to various conditions and traits, but very few of these studies have been conducted for sleep. Genome-wide association studies require large sample sizes; for example, in a recent report on the determinants of human height the sample size was 253 288 (Wood et al., 2014), and in another study on type 2 diabetes in African Americans 8284 cases and 15 543 controls were included (Ng et al., 2014). These are challenging sample sizes. In the present issue of the Journal of Sleep Research Ollila et al. report the results from a genome-wide association study of sleep duration in the Finnish population (Ollila et al., 2014). The discovery sample comprised 1941 individuals living in Finland. No genomewide significant associations (which would require a P-value
