The syndrome caused by JARID2 variants is characterized by developmental delay, intellectual disability, hypotonia, and autistic features. Behavioural abnormalities such as aggressive demeanor, tendency to obsessive/compulsive and perseverative behaviour, attention deficit–hyperactivity disorder (ADHD), and trouble with socialization are common. Seizures can also be found. Dysmorphic facial features include high anterior hairline, deep set eyes, full lips, broad forehead, infraorbital dark circles, bulbous nasal tip, and depressed nasal bridge.