e2/e3Published research associates this genotype with somewhat reduced lifetime risk compared to baseline.
e3/e3The most common genotype. Published research treats this as the baseline (average) risk level.
e3/e4One copy of the e4 allele. Published research associates this genotype with moderately elevated lifetime risk of late-onset Alzheimer's disease compared to baseline.
e4/e4Two copies of the e4 allele. Published research associates this genotype with substantially elevated lifetime risk of late-onset Alzheimer's disease compared to baseline.
This result does not predict whether or when Alzheimer's disease will occur. Talk to a doctor or a genetic counselor about what this means for you and your family.
Source: Corder et al. 1993, Science — gene dose of apolipoprotein E type 4 allele and the risk of Alzheimer's disease.