I think these studies are showing that there’s a lot more to the picture than ApoE. We are going to find more and more of these genes—maybe not to the same degree that ApoE is, but that will have their own role and they’ll work synergistically for or against the development of Alzheimer’s.
A recent study had hundreds of thousands of people in it, and they used a family history as their phenotype, meaning they took a look at a group of people and divided them between whether they had a family history or not. Then they looked at their genetic code and for specific gene mutations that were more associated with Alzheimer’s than not, or a family history or not. It doesn’t show a causal relationship; it doesn’t mean that these genes cause Alzheimer’s, but it showed a signal that they’re more associated with each other, and I think it’s important that we’re careful about that. Researchers discovered three new genes; two of them dealt with blood pressure and one dealt with a clotting factor. Frankly, the blood pressure one made a lot of sense. A lot of studies show the relationship between blood pressure and Alzheimer’s, and blood pressure and the development of the protein that leads to Alzheimer’s. I think we’re getting closer to finding more solid evidence for other genes, but I don’t think we’re at the point where we can say definitively that it’s ApoE, it’s this, and it’s this.