NRXN1 and schizophrenia: Recent data suggested that heterozygous variants or defects in NRXN1(Neurexin 1) or CNTNAP2 (contactin associated protein 2), both genes encoding neuronal cell adhesion molecules, represent susceptibility factors for a broad spectrum of neuropsychiatric disorders such as epilepsy, schizophrenia or autism spectrum disorder (ASD) with reduced penetrance and no or rather mild intellectual impairment [1-23].