November 1, 2026, 7:05 am | Read time: 4 minutes
An international study provides new insights into the genetic foundations of Alzheimer’s disease: Researchers identified 48 previously unknown risk regions in the genome. The findings could help in the long term to better understand the development of the disease and to develop new therapeutic approaches. What’s behind this?
Alzheimer’s is one of the most common causes of dementia. Although the disease is intensively researched, not all biological processes contributing to its development are fully understood. A large international genome study, published in the journal “Nature,” now provides new clues: Researchers identified 48 genetic regions that had not previously been associated with Alzheimer’s.1
For the study, the research team analyzed genetic data from around 2.8 million people. This included individuals diagnosed with Alzheimer’s, control subjects, and participants whose parents had Alzheimer’s. The large data set allowed researchers to investigate genetic connections that might have gone unnoticed in smaller studies.
What the Researchers Discovered in the Genome
In total, the team identified 127 genetic risk regions–118 in an analysis of various ancestry groups and nine more in analyses of individual groups. Forty-eight of these regions were previously completely unknown to science.
In genetics, such regions are referred to as loci. They mark areas in the genome where genetic differences are statistically linked to a disease. This does not mean that each of these regions alone causes Alzheimer’s. Rather, the disease is one of the complex illnesses where numerous genetic and other influences interact.
The researchers were also able to prioritize genes that might be involved in the observed connections. Some of these could eventually serve as starting points for new medications. However, further studies are necessary before concrete therapies can be developed.
Heritability Significantly Higher Than Thought
A key finding concerns heritability: Previously, the influence of common genetic variants on Alzheimer’s risk was estimated at only about 5 percent. The new study now shows that this genetic component is around 16 percent–about three times higher than previously thought. With refined risk profiles, it can also be shown that people in the top tenth of the risk scale have about a sevenfold increased risk of Alzheimer’s compared to the average.
An important limitation of the study: Over 90 percent of the data analyzed came from people of European descent. To make genetic risk profiles equally precise for all people worldwide in the future, further studies with more diverse participant groups are needed.
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What Role Do Immune Cells and Nerve Cells Play?
The results regarding certain cell types in the brain are particularly interesting. The analyses showed that genetic risk signals are associated, among other things, with microglia. These are immune cells of the central nervous system that, among other functions, clear away cell debris and are involved in inflammatory processes.
The study also suggests that genes with reduced activity in nerve cells in people with Alzheimer’s are also enriched with genetic risk signals. This could indicate that, in addition to immune processes, changes in nerve cells also play an important role in the disease.
The findings align with a research perspective in which Alzheimer’s cannot be attributed to a single mechanism. Instead, different biological processes seem to interact. The genetic findings help to examine these connections more closely. However, they do not automatically prove that a specific cellular change triggers the disease.
What Does This Mean for Diagnosis and Treatment?
For people who have Alzheimer’s or are concerned about their personal risk of developing the disease, the study does not initially result in any immediate changes. The newly identified genetic regions are primarily significant for research. They can help to better understand disease mechanisms and identify potential targets for future medications.
Does this mean that a genetic test can reliably predict Alzheimer’s? No. While risk profiles can be calculated much more accurately thanks to the new data, a genetic test still does not provide a definitive diagnosis. Whether the disease actually develops depends on many other life and environmental factors in addition to genes.
The main advancement of the study is therefore initially in the better understanding of the biological foundations of Alzheimer’s. Whether new diagnostic methods or more effective therapies can be developed from this will need to be shown by further studies.