Alzheimer's could be transmissible - under extremely rare circumstances. In very few cases, Alzheimer's could have been transmitted through a medical procedure that has not been used for a long time.
British doctors are now writing in the journal Nature Medicine about an extremely rare third type of Alzheimer's. The group bases the claim on case reports from eight people who were injected with growth hormone taken from the brain tissue of deceased people in their childhood. They therefore developed Alzheimer's symptoms a few decades later, at a noticeably young age.