Chromosomes in Alzheimer disease

Abstract

The purpose of this study is to determine if cytogenetic changes are present in Alzheimer disease. The chromosomes of four groups of people were studied: 1) cases of Alzheimer disease (13 cases, age range 38-62 years), 2) control individuals (12, 36-63 years), and 3) cases of senile dementia of Alzheimer type (6, 77-88 years), 4) senile control individuals (4, 80-91 years). Fifty cells per individual were examined using conventional Giemsa staining to allow chromosome identification.
A statistically significant increase in aneuploidy was found in 117 of 650 cells in Alzheimer group (18.0%, p<0.01) when compared with the frequency of aneuploidy in control group (3.5%). However, the frequency of aneuploidy in group of senile dementia of Alzheimer type (12.6%) did not differ significantly from senile control group (10.5%, p=0.1).
In addition, almost all of individuals in Alzheimer group exhibited a significant increase in aneuploidy over senile dementia group, raising the possibility that Alzheimer disease differs from senile dementia, since patients affected with Alzheimer disease are younger than individuals suffering from senile dementia, on the average. Furthermore, the missing and extra chromosomes in the two groups were consistenly the C-X group chromosomes. For further clarifying the origin of the aneuploidy, lymphocytes from an Alzheimer-patient were cultivated in Eagle's MEM medium containing serum from control individual.
It was found that the aneuploidy was derived from the lymphocytes, not from the serum or other factors.