Sometimes known as balancing selection, genetic polymorphism refers to the variations in genes which result in changes in the functions of a particular gene. This change in genetic function was the focus of this study conducted by Tina B. Lonsdorf and her team in which they found that there may be an association between genetic polymorphism and mental disorders.
Anxiety disorder is a blanket term for a number of abnormal and pathogenic disorders such as panic disorder, social anxiety disorder, obsessive compulsive disorder, post-traumatic stress disorder and of course, generalised anxiety disorder. Most of what is known about the causal factors of anxiety disorders is based upon symptoms that are learned.
However, in light of this recent finding, the causality of anxiety disorders may have a genetic basis. Focusing on the serotonin transporter gene and the gene for the enzyme COMT, it was found that individuals with a particular variation in the genes of interest were found to be more susceptible to attain and retain the fear associated with threatening and traumatic stimuli. To be more specific, participants in this study with the shorter version of the serotonin transporter gene were more likely to developed strong physiological responses to threatening and traumatic stimuli. In regard to the gene for the enzyme COMT, participants with a variation of the coding sequence were more likely to overcome their fear.
This study makes significant advances in the interaction between genes and the environment as it shows the environment acting as a kind of trigger for anxiety disorders for those individuals with particular variations in the associated genes.
