For quite a while now, researchers have been trying to figure out just exactly when the changes in the brain that are linked with Alzheimer’s Disease first begins. Now, there is a new study that might show that they could began at birth, as early as six months old. A new report was released by JAMA Neurology that shows that infants who carry a specific gene, APOE-E4, which is a variant that is linked with an increased risk for Alzheimer’s, also is different in the development of the brain for children that do not have the APEO-E4 gene. Three different version of the gene exist, known as E2, E3 and E4 and the E3 version is the most common one.
Twenty-five percent of the United States population has the E4 gene already, and researchers have known that the gene is a marker for the risk of late Alzheimer’s. However, not everyone that has the gene will get the disease, around sixty percent of those people that have Alzheimer’s do have at least one copy of that E4 gene. It plays several different roles in the human brain, but the disease is not fully understood, and clearly there is something else going on here than just the gene itself, since forty percent of Alzheimer’s patients do not even have the gene. However, researchers are working hard to try to understand how the disease works.
“We’re not really sure what that gene does; why does it confer risk?” said Sean Deoni, who is one of the Senior Authors on the study. “We don’t have a good handle on that. The hypothesis is that it’s involved in the maintenance of myelin sheath” That is the layer that surrounds and insulates the nerves that are located in the brain and the spinal cord. Alzheimers and other diseases cause damage to the myelin sheath, those that have the E4 gene might not have the ability to repair cells that can lead to Alzheimer’s.