Head circumference at birth is significantly below average (3 SD below the mean). Typically, with mild to moderate cognitive impairment, that does not worsen over time. Aside from small head, affected individuals usually have normal facial features and body proportions.
Most children achieve motor milestones, although some may have mild delays. Seizures and neurological deficits are generally absent or uncommon. Reduced brain volume, especially in the cerebral cortex, with simplified gyral patterns (pachygyria-like appearance) but structurally normal brainstem and cerebellum.
CtIP