But genetic testing alone is unlikely to be an accurate predictor, because around half of Alzheimer’s sufferers do not carry ε4, and probably half of those with ε4 do not develop the disease. Moreover, though international studies of more than 70,000 people have found over 20 other genes linked to Alzheimer’s, their impact is minimal.
但光靠基因测试无法作为准确的指标，因为大约一半的阿尔茨海默症患者不携带ε4，并且可能有一半的ε4携带者不会发生阿尔茨海默症。此外，尽管对70,000多人的国际研究表明有20多个基因与阿尔茨海默症有关，但它们的作用很小。