By NIH Research Matters –
Variations in certain genes can modify the risk of developing Alzheimer’s disease (AD) and other types of dementia. Some of the best understood variants to date are in a gene called APOE. This gene plays a role in the transport of cholesterol and other fatty molecules in the brain and body. People with a variant of APOE called APOE4 have an increased risk of developing AD dementia. In contrast, people with a variant called APOE2 appear to have some protection against developing dementia.