<i>GABBR1</i> pathogenic variants have been recently associated with mild to severe psychomotor delay, epilepsy, intellectual disability (ID), autism (ASD), attention deficit hyperactivity disorder (ADHD) and oppositional defiant disorder (ODD).<h4>Material and methods</h4>We report a 13.9-year-old girl, with a complex neurodevelopmental disorder including ASD, ID with the appearance, at 9 years of age, of vocal and motor tics involving the upper limbs and trunk, suggesting a diagnosis of Tourette's syndrome (TS). This evidence concerns the gene GABBR1 and Oppositional defiant disorder.