Here we aim to define the neuropsychiatric profile associated with PCDH19 pathogenic variants using standardized assessments that specifically target executive functions and symptoms associated with ASD, attention-deficit hyperactivity disorder (ADHD), and obsessive-compulsive disorder (OCD), and interrogate which factors predict the severity of these neuropsychiatric comorbidities. Here, PCDH19 is linked to attention deficit-hyperactivity disorder.