DLG2 and autism spectrum disorder: The findings of Nithianantharajah et al.,35 as well as those discussed here, together may be interpreted as being indicative of cognitive inflexibility in models of Dlg2 haploinsufficiency or knockout, a symptom seen in schizophrenia,41, 44, 45 autism spectrum disorder,38, 39 and attention deficit hyperactivity disorder,40, 43 for which genetic variations in Dlg2 are a risk factor for.