A report published in the Archives of Neurology (January 2003) indicated that people with a polymorphism in the CYP46 gene are at increased risk for late-onset Alzheimer?s disease (AD). According to researchers, this gene encodes cholesterol 24-hydroxylase, and previous studies have shown that reducing cholesterol levels in the brain inhibits the generation of beta-amyloid peptides found in AD plaques.
The study compared 201 patients with AD with 248 control subjects to assess the CYP46 genotype and the frequency of a particular polymorphism. Researchers found the CYP46*TT genotype to be significantly more common among the patients with AD. The study authors concluded that ?these data are consistent with the possibility that CYP46 is a novel susceptibility gene for Alzheimer?s disease.?