Studies in aging of the brain: IV. Familial Alzheimer disease: Relation to transmissible dementia, aneuploidy, and microtubular defects.

Alzheimer disease was transmitted in a pattern consistent with an autosomal dominant trait in three families. This brings to 50 the number of such families reported. In one of our families, one patient had histologically confirmed Alzheimer disease, whereas her sister had proved spongiform encephalopathy. Other data suggest a link between familial Alzheimer disease and transmissible dementia. Alzheimer disease is associated with abnormal neurofibrillary structures, Down syndrome, and abnormal numbers of chromosomes in lymphocytes (aneuploidy). These observations are consistent with a disorder in the physiology of tubular-filamentous structures involving different cell types.