Common functional polymorphisms in SLC6A4 and COMT genes are associated with circadian phenotypes in a South American sample.

The molecular study of circadian rhythms in humans could be an excellent approach to understand the relation between genes and behavior. It is possible that variations in genes involved in neurotransmission and/or synaptic plasticity, such as catechol-O-methyltransferase (COMT) and serotonin transporter (SLC6A4) could be of particular interest in understanding human circadian phenotypes. The aim of this study is to analyze the possible and novel associations of the functional polymorphisms in COMT and SLC6A4 genes (Val158Met and 5-HTTLPR) and circadian phenotypes in healthy Colombian subjects.