Chromosome changes in Alzheimer's presenile dementia.

Lymphocyte chromosomes were examined in 36 patients with Alzheimer's presenile dementia, 36 healthy, age and sex matched controls, and 36 sex matched, non-demented, elderly controls, approximately 20 years older than the Alzheimer patients. Increased chromosome aneuploidy was found in females with Alzheimer's disease but not in male subjects. Chromosome abnormalities observed in female patients were similar to those observed in elderly controls, though in this latter group there was an increase in the frequency of cells that had lost an X chromosome. In the female Alzheimer patients and the elderly controls, there was an increase in the frequency of autosomal aneuploid cells but no single chromosome was preferentially affected. Because the chromosome abnormalities found in Alzheimer's disease are similar in nature but not as extensive as those observed in senescence in the absence of dementia, it is argued that chromosome aneuploidy is more likely to be related to processes concerned with ageing rather than being specifically linked to the dementia of Alzheimer's disease.