A woman, who had been developmentally delayed since her birth, further deteriorated after she got an episode of high fever of unknown origin at 2 years of age. At the age of 52 years, she died of liver cancer after a long-standing HB virus carrier state. Neuropathological examination revealed brain atrophy, narrowed white matter, myelin pallor, fibrillary gliosis and status marmoratus of the thalamus. These findings suggested the primary cause of the brain pathology in this case to be a developmental destructive process which should have taken place in the early stage of brain development. In addition, neurofibrillary tangles (NFT) were noticed in the hippocampus, locus ceruleus and nucleus basalis of Meynert, but no senile plaques were found anywhere. These NFT changes seemed to be closely resembling to those of the Fukuyama type congenital muscular dystrophy. But the reason why NFT occur in this case is still obscure and probably different from that in the Down syndrome or in physiological senility.