Déterminants génétiques des idées délirantes

Abstract

The use of symptom dimensions of schizophrenia (positive, negative and disorganised) as quantitative phenotypes has been proposed as a mean to reduce the heterogeneity of schizophrenia and facilitate genetic research. The aim of the present study was to summarize the results of studies investigating the genetic background of the positive dimension. Several studies suggest a genetic contribution to the reality distortion dimension, but at a lesser degree than for the disorganised dimension. Few studies have investigated relationships between genetic factors and reality distortion dimension. However, some works suggest that genetic variation in DISC1 and COMT may be associated with delusions and hallucinations. As specific cognitive deficits have been suggested as explanations for the positive dimension, new strategies should focused on their correlations with genetic factors. For example, source-monitoring deficits (a presumed cognitive marker for increased proneness to psychotic symptoms) can be observed in subjects with 22q11 deletion syndrome, a region containing candidate genes such as Catechol-O-Methyltransferase ( COMT) gene.