rs6583817

rs6583817, also known as v311, is a SNP within an intron of the IDE gene, which encodes the insulin-degrading enzyme. Late onset Alzheimer's disease is a neurodegenerative condition in which the brain develops large numbers of extracellular senile plaques composed primarily of aggregated amyloid-B proteins as well as intraneuronal neurofibrillary tangles composed mainly of aggregated tau protein. One notable function of insulin-degrading enzyme is its ability to degrade amyloid-B and therefore to influence the amount of amyloid-B found in the brain. A study of ~3,000 patients (and an equal number of matched controls) found that carriers of one or two minor alleles, i.e. rs6583817(T), had ~2x higher levels of insulin-degrading enzyme (p < 10e-8), lower levels of amyloid-B, and a (slightly) lower risk of Alzheimer's disease, with an odds ratio of around 0.80 (p < 0.03), depending on the population studied. rs6583817 is thought to be a functional variant based on in vitro studies. While rs6583817 may be a functional variant, it is nearly perfectly linked to nearby SNP rs7910977, which is more commonly found on Illumina microarrays. The rs7910977(T) allele was also shown to correlate with decreased amyloid-B levels (presumably due to linkage with rs6583817), and it can be used to predict the presence of a rs6583817(T) allele.