What role does genetics play in Alzheimer’s Disease?
Scientists know genes are involved in Alzheimer’s. There are two categories of genes that can play a role in determining whether a person develops a disease. Alzheimer genes have been found in both categories: 1) Risk genes increase the likelihood of developing a disease, but do not guarantee it will happen. Scientists have so far identified one Alzheimer risk gene called apolipoprotein E-e4 (APOE-e4). APOE-e4 is one of three common forms of the APOE gene ( the others are APOE-e2 and APOE-e3). APOE provides the blueprint for one of the proteins that carries cholesterol in the bloodstream. Everyone inherits a copy of some form of APOE from each parent. Those who inherit one copy of APOE-e4 have an increased risk of developing Alzheimer’s. Those who inherit two copies have an even higher risk, but not a certainty. In addition to raising risk, APOE-e4 may also tend to make symptoms appear at a younger age than usual. Experts believe there may be as many as a dozen other Alzheimer risk gen
