The 3111TC polymorphism interacts with stressful life events to influence patterns of sleep in females

Abstract

Genetic variations in clock-relevant genes have been investigated in relation to sleep abnormalities, both in healthy populations and in mood-disorder patients with inconsistent results. Environmental influences may moderate associations between genes and phenotype. The authors examined the CLOCK 3111TC polymorphism and several variants within the PER3 gene and their possible interaction with stressful life events in a group of female volunteers (n415). Gene-environment (G×E) interactions and gene main effects were investigated on depressive symptoms using the Beck Depression Inventory and on change of sleep patterns (Item 16). Results showed a G×E interaction on alteration of sleeping pattern: the 3111C homozygous genotype reported greater disruption in sleep pattern after the experience of stressful life events. Within the PER3 gene, one G×E interaction was observed with rs228642 on sleep change. These findings show that the 3111TC polymorphism is not associated with depressive symptoms, but only with symptoms of sleep change in the case of prior stressful life experiences. The combination of a sensitive genotype (3111CC) and environmental stress increases vulnerability to circadian rhythm disruption in females. © Informa Healthcare USA, Inc.