The findings of a new study published in January's Archives of Neurology suggests that a new gene called CYP46 may play a role in some cases of Alzheimer's disease. A variation in the gene, which is involved in the production of an enzyme that helps break down excess cholesterol in the brain, may result in the buildup of cholesterol and a gummy protein called beta amyloid, in the brain.
Earlier studies have shown that elevated cholesterol levels may raise the risk of Alzheimer's. There is also previous evidence that Alzheimer's is related to variation in another gene called APOE-4, which helps in transporting cholesterol throughout the body. In the new study which involved more than 400 patients with or without Alzheimer's, the CYP46 variant was found in about 40 percent of participants. It was observed in the study that patients with both the CYP46 and APOE-4 variants were almost 10 times more likely to develop the mind-robbing disease than those with neither variation. These patients also had the highest brain levels of beta amyloid. Autopsies of patients with just the CYP46 variant revealed significantly higher levels of beta amyloid deposits than those without the variant.
Dr. Benjamin Wolozin of Loyola University Medical Center in Maywood, said in an accompanying editorial that this and earlier studies suggest that inhibiting cholesterol breakdown in the brain might represent a viable treatment for Alzheimer's.