The genotypic variants of the COMT Valine158Methionine polymorphism (COMT Val(158)Met) have age and sex specific effects on brain structure and function in children and adolescents. An age reversal of genotypic effect of COMT Val(158)Met on attenuation in cortical thickness in bilateral PFC (medial and lateral aspects), temporal, and superior parietal regions was found in healthy controls from 9 to 22 years of age (Raznahan et al., 2011b). From ages 6 to 20 there is an age reversal in the genotypic effects on performance in a working memory task and a corresponding variation in the activation level of of the right inferior frontal gyrus and intraparietal sulcus (Dumontheil et al., 2011). These variants have effects on auditory evoked potentials in adults (Heitland et al., 2013; Saville et al., 2014). In 9 year olds, effects on IQ and executive function are found only in males, and are stronger in in pubertal than in prepubertal males (Barnett et al., 2007).
