Susceptibility genes for schizophrenia affect normal individuals

In the largest study of its kind to date, we sought to examine the impact of several genes that have been previously associated with schizophrenia susceptibility, such as Catechol-O-methyltransferase (COMT), Neuregulin1 (NRG1), Dysbindin (DTNBP1), D-amino-acid oxidase activator (DAOA), D-amino-acid oxidase (DAAO) and the regulator of G-protein signaling 4 (RGS4), on a healthy population. We recruited more than 2000 young men and measured dimensions of their cognitive abilities and schizotypal personality traits. Healthy individuals who possessed the risk variants within the DNTBP1, NRG1, COMT, DAAO and RGS4 genes exhibited selective and small reductions in their cognitive performance and in general had higher schizotypy scores. Even at the general population level, the genetic liability to psychosis may be expressed as minute and ‘undetected to the naked eye’ alterations in brain information processing capacity and behavior.