title: Genetic Correlation Analysis Suggests Association between Increased Self-Reported Sleep Duration in Adults and Schizophrenia and Type 2 Diabetes.
abstract: We sought to examine how much of the heritability of self-report sleep duration is tagged by common genetic variation in populations of European ancestry and to test if the common variants contributing to sleep duration are also associated with other diseases and traits.
  
  
  
  We utilized linkage disequilibrium (LD)-score regression to estimate the heritability tagged by common single nucleotide polymorphisms (SNPs) in the CHARGE consortium genome-wide association study (GWAS) of self-report sleep duration. We also used bivariate LD-score regression to investigate the genetic correlation of sleep duration with other publicly available GWAS datasets.
  
  
  
  We show that 6% (SE = 1%) of the variance in self-report sleep duration in the CHARGE study is tagged by common SNPs in European populations. Furthermore, we find evidence of a positive genetic correlation (rG) between sleep duration and type 2 diabetes (rG = 0.26, P = 0.02), and between sleep duration and schizophrenia (rG = 0.19, P = 0.01).
  
  
  
  Our results show that increased sample sizes will identify more common variants for self-report sleep duration; however, the heritability tagged is small when compared to other traits and diseases. These results also suggest that those who carry variants that increase risk to type 2 diabetes and schizophrenia are more likely to report longer sleep duration.
authors.affiliation: The University of Queensland, Queensland Brain Institute, Brisbane, Australia.|Center for Sleep and Circadian Neurobiology, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA.
authors.forename: Enda M
authors.initials: EM
authors.lastname: Byrne
authors.affiliation: Center for Sleep and Circadian Neurobiology, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA.|Behavioral Sleep Medicine Program, Department of Psychiatry and Penn Sleep Center, University of Pennsylvania, Philadelphia, PA.
authors.forename: Philip R
authors.initials: PR
authors.lastname: Gehrman
authors.affiliation: The University of Queensland, Queensland Brain Institute, Brisbane, Australia.
authors.forename: Maciej
authors.initials: M
authors.lastname: Trzaskowski
authors.affiliation: Department of Child and Adolescent Psychiatry/Psychology, Erasmus MC-Sophia, Rotterdam, The Netherlands.|Department of Psychiatry, Erasmus Medical Centre, Rotterdam, The Netherlands.|Department of Epidemiology, Erasmus Medical Centre, Rotterdam, The Netherlands.
authors.forename: Henning
authors.initials: H
authors.lastname: Tiemeier
authors.affiliation: Center for Sleep and Circadian Neurobiology, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA.
authors.forename: Allan I
authors.initials: AI
authors.lastname: Pack
mesh_terms: D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology / Q000235:genetics*; D005260:Female; D014644:Genetic Variation / Q000235:genetics; D055106:Genome-Wide Association Study / Q000379:methods*; D006801:Humans; D015810:Linkage Disequilibrium / Q000235:genetics; D008297:Male; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D012559:Schizophrenia / Q000453:epidemiology / Q000235:genetics*; D057566:Self Report; D012890:Sleep / Q000235:genetics*; D013997:Time Factors
keywords: GWAS; genetics; sleep duration; type 2 diabetes