Two-dimensional gel electrophoresis of human brain proteins. III. Genetic and non-genetic variations in 145 brains.

To determine the frequency of genetic mutations, polymorphisms, and non-genetic variation in the major human brain proteins, I examined, by equilibrium two-dimensional gel electrophoresis, 145 brains from patients dying of a wide variety of psychiatric, neurological, and non-neurological disorders. Of 176 polypeptides screened, there was one polymorphism of glial fibrillary acidic protein (GFAP-Duarte). Chi square analysis indicated it was non-randomly distributed among different diseases. A possible mutation associated with Joseph's disease is being further investigated. Three examples of a possible mutation of protein 8c:1 were noted. No other genetic mutations were observed. This low frequency of polymorphisms is consistent with results for two-dimensional gel analysis of other tissue and species. The numerous non-genetic variations are described.