The best article I have read that clearly explains the genetic components and risks of developing Alzheimer's. The components I am referring to are the genes themselves. There are various genes that have various levels of risk. Meaning with most Alzheimer's genes there is a higher risk that you will get the disease than without the gene. Other, very rare genes are much more serious. The article does a much better job than I am doing... go read it here.
By the way... sign up on the Alzheimer's Prevention Registry while you are there. Just click the Home link at the top of the page. Thanks. - Brian