PVALB and Timothy syndrome: TS or chronic tic disorder affects ∼1–2% of children and adolescents and is the most common form of movement disorder in children.1 The pathophysiology of TS has been linked to dysfunction within cortical-striatal-thalamic-cortical (CSTC) brain circuits involved in the selection and initiation of movements.2,3 Specifically, TS is associated with a reduction in the number of inhibitory fast-spiking parvalbumin interneurons in the striatum,2 and it has been proposed that this might lead to increased neural ‘noise’ within the striatum and to downstream thalamo-cortical sensorimotor networks.3