Cyp46 Polymorphisms in Alzheimer's Disease: A Review

Increasing research findings argue for a link between brain cholesterol turnover and Alzheimer's disease (AD). High cerebral levels of this lipid increase A beta load. The elimination of cerebral cholesterol involves two mechanisms, dependent of apolipoprotein E and cholesterol 24-hydroxylase (CYP46). CYP46 is a gene associated with AD; the most studied single nucleotide polymorphism is the rs754203, which changes T. C. Some studies describe that this polymorphism is possibly associated with loss of function of CYP46; others describe that it is possibly associated with cerebral cholesterol accumulation or an increase of CYP46 activity leading to an accumulation of the 24S-hydroxycholesterol in cerebrospinal fluid. Publications about this subject around the world are controversial. Some studies associate the T allele with AD and others the C allele. The aim of this review is to describe and summarize the findings of the researches about the relationship between CYP46 and AD that have been published in the past 9 years.