Angelman's syndrome: a neuropathological study.

We report the neuropathological findings of a 3-year-old boy with Angelman's syndrome. The main abnormalities were macroscopic consisting of small temporal and frontal lobes which also showed disorganised and irregular gyri. The occipital lobes appeared flattened but were otherwise normal as were the parietal lobes. The brain stem and cerebellum appeared normal externally. Microscopically there was irregular distribution of neurons in layer 3 and in the cerebral white matter a few subcortical ectopic neurons were present in the temporal and frontal lobes. A single "Purkinje" cell heterotopia was seen but otherwise the cerebellum appeared normal.