“About 60 percent of the patients we see in the Alzheimer’s clinics have at least one copy of APOE 4,”
Scientists’ picture of how a gene strongly linked to Alzheimer’s disease harms the brain may need to be revised.
People with harmful forms of the APOE gene have up to 12 times the risk of developing Alzheimer’s disease compared with those who have other variations of the gene.
Many researchers believe that the memory loss and cognitive problems of Alzheimer’s result from the buildup over many years of brain amyloid plaques. The plaques are made mostly of a sticky substance called amyloid beta.
For years, researchers have thought that the APOE gene increases Alzheimer’s risk by producing a protein that binds to amyloid beta. Scientists thought that this bond could make it easier for plaques to form.
But a new study shows that APOE and amyloid beta don’t bind together in cerebrospinal fluid and in fluids present outside cells grown in dishes.