Can genetic testing predict Alzheimer's?

Genetic testing can indeed predict an increased risk of developing Alzheimer's disease, particularly through the identification of the APOE gene variant. The APOE4 allele is significantly associated with Alzheimer's. However, it is not deterministic, meaning having the allele increases the likelihood but does not guarantee the development of Alzheimer's. About 25% of the general population carries at least one copy of the APOE4 gene, and this portion accounts for two-thirds of all Alzheimer’s cases. Even with two copies of the APOE4 allele, not everyone will develop the disease, indicating the influence of other genetic and environmental factors 1.

There are also rare genes, such as PSEN1, PSEN2, and APP, that almost guarantee the development of Alzheimer's if present, but these are extremely uncommon, accounting for less than 1% of cases 1.

Genetic testing is available and can identify these risk factors, thereby allowing individuals to take preventive measures. However, over-reliance on genetic results and the attendant anxiety are cautioned against, as these can lead to unnecessary stress without providing actionable solutions outside research settings 1 2.