A new study suggests that having two copies of a gene variant called ApoE4 might be more than just a risk factor for Alzheimer’s disease, it could actually be a distinct form of the disease itself.
Previously, scientists knew ApoE4 increased the chances of developing Alzheimer’s, with two copies posing a greater risk than one. This new research indicates that nearly everyone with two copies will go on to get the disease.
Researchers analyzed brain tissue from over 3,000 donors and found that almost all of the 273 individuals with two ApoE4 copies had signs of Alzheimer’s in their brains. Additionally, data from over 10,000 people showed that by age 65, nearly all of those with two copies had abnormal levels of a protein linked to Alzheimer’s in their spinal fluid.
This new understanding could have significant implications. With roughly 2% of the population carrying two copies of ApoE4, this form of Alzheimer’s disease could be one of the most common single-gene diseases. The earlier disease onset (around 65 years old) in this group highlights the potential need for tailored treatment approaches.
However, some researchers aren’t convinced. They argue that the underlying processes seem similar across all Alzheimer’s cases, regardless of ApoE4 copies. This viewpoint suggests any future treatments might still be broadly applicable.
Further research is needed, particularly to see if these findings hold true for people of diverse ethnicities. The current study largely involved participants with European ancestry.
Overall, this research offers a new perspective on Alzheimer’s disease, potentially paving the way for more targeted therapies and support programs for those most at risk.