Interactions between season of birth, chronological age and genetic polymorphisms in determining later-life chronotype.

•Genetic variants that are related to epigenetic regulations and DNA repair may be associated with age-dependent variations of chronotype.•Postnatal seasons may program biological rhythms via epigenetic alterations and neural development.•Some polymorphisms contribute towards inter-individual variation in season of birth effect.•Previously reported genetic variants that were associated with chronotype could not fully explain the longitudinal change of chronotype.