AP1S2-related syndrome presents with a large intrafamilial clinical variability.
Intellectual disability is mostly severe and preceded by progressive developmental delay.
Delayed walking with gait abnormalities and progression to major handicap in adulthood have been reported in several patients; several patients never walked.
Verbal communication is extremely poor, with about 40% having no words.
Aggressive or compulsive self-harm behavior is common.
Eye problems are noted.
Epilepsy and autistic spectrum disorders have been reported.
Lumbar puncture may detect not specific abnormalities.
Most female carriers of a mutation in the AP1S2 gene have normal intelligence and normal phenotypes.
AP1S2