Genetic-Evidence That the Lewy Body Variant Is Indeed a Phenotypic Variant of Alzheimers-Disease

Lewy Body Variant (LBV) patients present as Alzheimers disease (AD) clinically; about two-thirds also have mild extrapyramidal features. At autopsy, neocortical and brain stem Lewy bodies are present in addition to changes diagnostic of AD. We have found that the Apolipoprotein E4 allele is a major genetic risk factor for LBV as it is for ′pure AD," in contrast to subjects with diffuse Lewy body disease or Parkinsons disease. This genetic evidence supports the concept that LBV-the second most common neurodegenerative form of dementia-is a phenotypic variant of AD.