Mini-Review Background

Most psychiatric and neurodevelopmental disorders (PNDD) have a strong heritable component.1 Twin studies have proved that neurodevelopmental disorders, such as attention deficit hyperactivity disorder (ADHD),2 autism spectrum disorders (ASD),2 as well as psychiatric conditions like Schizophrenia3 (SCZ) and Bipolar Disorder4 (BD) have an important genetic background. Nevertheless, until very recently, causal genes have only been found in the context of Intellectual Disability (ID). Classical genetic studies have failed to identify genes with high penetrance in PNDD, thus indicating that the genetic background of these disorders is highly heterogeneous. Recent developments in DNA analysis and sequencing, such as next-generation sequencing, SNP arrays, exome sequencing or analysis of copy number variations (CNVs),5,6 allow to study the whole genome of large cohorts of affected individuals, enablin