A variation in a gene that is supposed to help the brain break down cholesterol may play a role in some cases of Alzheimer’s disease, researchers say.
A study found that people with this variant form face double the risk of developing late-onset Aizheimer’s, which typically develops after age 65.
The gene, called CYP46, is involved in production of an enzyme that helps break down excess cholesterol in the brain. The research suggests that the variation might hamper production of the enzyme, causing a buildup in the brain of cholesterol and a gummy protein – beta amyloid.
It also adds to evidence that genetics are involved. Late-onset Alzheimer’s already has been linked to another genetic variation in a different gene involved in helping transport cholesterol throughout the body. That variation is called APOE-4.
In the new study, patients with both the CYP46 and APOE-4 variants of the gene were almost 10 times more likely to develop the mind-robbing disease than those with neither variation. They also had the highest brain levels of beta amyloid.