PANK1 and atypical Rett syndrome: Finally, the association between tics and stereotypies has been reported in a number of other neuropsychiatric conditions characterised by behavioural and cognitive abnormalities, such as Rett syndrome [36], Primrose syndrome [37], a juvenile progressive dystonia suggestive of pantothenate kinase-associated neurodegeneration (PKAN) [38], and behavioural disturbance associated with anti-basal ganglia antibodies [39].