The APOE (apolipoprotein E) gene is involved in making certain proteins. People who carry APOE4, a version of the gene, have an increased genetic risk of developing Alzheimer’s disease. Knowing whether someone carries APOE4 helps scientists look for early brain changes in study volunteers and compare the effectiveness of treatments for people with different versions of the APOE gene. About half of the people carrying one copy of the APOE4 gene will never develop the disease. The risk of Alzheimer’s is increased further for people with two copies of the APOE4 gene.
APOE testing is not routinely available on Medicare. Some people may be aware of whether they have it if they have taken a private genetic test or been told as part of a previous research study.
