Why some people cope better with stress and some fold under the pressure? This can be explained with COMT gene. It is one of the most important markers associated with intelligence and personality. COMT gene codes for the COMT enzyme which breaks down dopamine in the prefrontal cortex. This is the part of the brain that is responsible for planning, decision making, cognitive ability, problem-solving, reasoning. COMT gene marker (SNP) has two alleles. Please remember that this one marker does not define You as a person thou, but is related to the statistical findings.