severe: no development, some: spontaneous bottle feeding, looking, similng, roll from side wo back/front, they lose skills 3-4 mo old. <6 mo: progressive spasticity, cortical blindness,swallowing difficulty. 1st year: intractable seizures, hypsarrythmia, multifocal spikes, scoliosis hip dislocation, may be microcephaly, cleft palate, clubfeet