For more than 30 years, Alzheimer’s researchers have thought of APOE4 as a major genetic risk factor for most cases of the devastating neurologic disease. But a new study published on Monday argues that this gene variant plays an even more important role than scientists had realized and causes a distinct form of Alzheimer’s.
Researchers analyzed data from more than 13,000 people, including nearly 800 APOE4 homozygotes, people who carry two copies of the gene variant. They found that nearly all of the homozygotes showed biological signs of Alzheimer’s in the brain, and they typically developed dementia and other symptoms, and died sooner, than people with Alzheimer’s who lack APOE4.
The research team also found that APOE4 homozygotes showed a predictable pattern of biomarker changes linked to Alzheimer’s, including a buildup of beta-amyloid and tau, a protein linked to neuron damage and death.
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