Patients with GRIA1-4-related disorder have global developmental delay, which is apparent from infancy or early childhood. The disorder results in variable intellectual disability ranging from mild impairment with an ability to attend special schools to profound impairment with absence of speech and none to limited social skills to. Although the majority of patients eventually learn to walk, most are late to reach this milestone and have an unsteady gait. Some may experience developmental regression or stagnation and many have behavioral difficulties including autistic features, reduced attention span, auto-aggression, anxiety, and hypersensitivity to stimuli. While some patients have congenital hypotonia (loss of body tone), other affected infants show irritability, stiffness, and hypertonia early in life, which progresses to spasticity and impaired gait later. In addition, some patients may develop epileptic seizures of variable severity early in life.
GRIA1/GRIA2/GRIA3/GRIA4