People who have the APOE e4 gene variant are at an increased risk of developing Alzheimer's disease, but not all do, and, as Scientific American writes, researchers have homed in on another gene variant that may offer some protection against the disease.
As they report in JAMA Neurology, researchers from Stanford University conducted a meta-analysis of 22 Alzheimer's disease cohorts that encompassed more than 20,000 participants. In particular, they sought to examine whether also being heterozygous for a Klotho haplotype called KL-VS — which previous work has indicated promotes health aging and longevity — affects APOE e4 carriers' risk of developing Alzheimer's disease. Being heterozygous for KL-VS, they found, was associated with reduced Alzheimer's disease risk among people between 60 and 80 years of age.
"In this APOE4 carrier group, carrying one copy — but not two — of the klotho variant reduced Alzheimer's risk by 30 percent," first author Michael Belloy from Stanford tells HealthITAnalytics.
Scientific American adds that this finding could add a layer of accuracy to studies using APOE e4 carriers to investigate drugs to stave off the development of Alzheimer's disease by enabling them to avoid carriers who also are heterozygous for KL-VS and might not develop the disease as readily.