How are the changes in the phenotype Alzheimer’s Disease being transmitted?

Answer 1

Hello Adrianna,

By using "transmitted" in your question, I'm assuming you are referring only to the genetic basis of Alzheimer's disease and not non-genetic risk factors. Please clarify if not. I don't entirely understand your question, but I'm going to give it a shot and please feel free to respond if I don't answer it. We can have a running dialogue.

The molecular basis of disease involves genetic mutations. Unlike the single gene disease hypothesis you may come across in elementary textbooks, the genetics of AD is suspected to involve several genes with one or more mutations that are considered risk factors. To complicate matters further, there are even non-coding regions in the genome that have mutations that seem to be involved!!! Scientists are actively identifying new genetic loci that contribute to disease severity as we speak (or type). Of course you will find a couple well-studied genes APP, PSEN1, and PSEN2 discussed in the mainstream media.

Just like other genetic traits, non-coding and coding loci can be passed onto offspring through meiosis. The disease burden will depend on the types of mutations the offspring inherits. For example, early onset familiar alzheimer's disease is inherited in an autosomal dominant manner in the case of APP, PSEN1, and PSEN2 gene mutations.