atypical juvenile parkinsonism (MONDO_0018321) (AJP) is a complex form of young-onset Parkinson disease (YOPD) that manifests with pyramidal signs, eye movement abnormalities, psychiatric manifestations (depression, anxiety, drug-induced psychosis, and impulse control disorders), intellectual disability, and other neurological symptoms (such as ataxia and epilepsy) along with classical parkinsonian symptoms.