Effects of gene copy number variants on personality and mood in ageing cohorts

Personality traits show substantial heritability but their genetic foundations are poorly understood. This study investigated whether structural genetic variation - specifically, copy number variants (CNVs) where segments of the DNA have been deleted or duplicated - contributed to variation in personality and mood in later adulthood. The Big Five personality traits and symptoms of anxiety and depression were measured in two Scottish cohorts aged 81 (N= 423) and 70. years (N= 877). Neuroticism, Extraversion and depressive symptoms were measured in an English cohort aged 41-86. years (N= 1547). Trait scores were regressed on: (1) number of CNVs ≥500. kb and ≤5% frequency, (2) total length of CNVs, and (3) number of genes they disrupted. Analyses were repeated for deletions and duplications. Agreeableness correlated (-0.07, p<0.05) with the number of genes affected by CNV duplications, but not at a level expected above chance. In this first CNV study of personality traits and mood symptoms, no support was found for a causative role of large, uncommon CNVs. Larger studies are needed to investigate rarer CNVs, and improvements in CNV prediction are needed to consider smaller CNVs using single nucleotide polymorphism data. © 2011.