Continuity between schizophrenia and autism spectrum disorder-From the view point of genomic copy number variation

Abstract

In the diagnostic criteria of DSM‐5, schizophrenia and autism spectrum disorder (ASD) are distinguished as different psychiatric disorders based on clinical symptoms. However, recent epidemiological and clinical studies have pointed out the existence of a continuum between the two disorders. Genomic studies have identified many cross‐disorder variants involved in the pathogenesis of both disorders. Among others, low frequency genomic copy number variations (CNVs ; including deletions and duplications) , such as 22q11.2 deletion, 15q11.2‐q13.1 duplication, and 3q29 deletion, have been reported to be involved in both schizophrenia and ASD. In‐depth analyses of CNV data have also found the similarities in pathological mechanisms of both disorders. In future studies, the relationship between schizophrenia and ASD may be clarified by following clinical symptoms from childhood to adulthood in subjects with these CNVs. In addition, neurobiological analyses using CNV‐based animal models and patient‐derived iPS cells are expected to elucidate the neural basis of both disorders.