APOE4 Gene Alzheimer’s Disease Testing For Women
In terms of this APOE4 gene and women’s risk of Alzheimer’s disease, it’s very interesting to note that human beings have what are called sexually dimorphic brains. What does that mean? That means if you look at the brain on autopsy, it’s actually possible to determine if this is a man’s brain or if it’s a woman’s brain, because there are structural differences between a man’s brain and a woman’s brain.
Where do those structural differences take place? Well, one area happens to be the region of the brain responsible for short-term memory that is particularly effected in Alzheimer’s disease and that’s called the hippocampus. In men, it turns out that the hippocampal volume tends to be larger and that there are more connections as well as the ability to produce the neurotransmitter acetylcholine, which is deficient in Alzheimer’s disease compared to women.
Why that is may be related to this APOE4 gene and its relationship to both estrogen and the X chromosome. In other words, the combination of the female hormone, estrogen, and the fact that women, compared to men, have two X chromosomes and do not have a Y chromosome, may together interact along with something called an HPA axis to impair a woman’s protective effect against developing this disease.