A lissencephaly syndrome characterized by smoothness of the surface of the brain (lissencephaly type II), agyria, thickening of the cortex, and other brain abnormalities in association with severe mental retardation, eye defects, genitourinary abnormalities, hydronephrosis, and other defects with or without encephalocele (written plus or minus E). Many characteristics of this syndrome overlap those of the cerebro-oculo-cerebral syndrome.