Scientists Discovered a Genetic Mutation That May Protect Against Alzheimer’s

KennySci/Tech2025-07-158890

A new study suggests a gene mutation could have a protective effect against Alzheimer's.

The research looked specifically at blood stem cells, which live in the bone marrow and make different types of blood cells.

Here's what you should know about the blood stem cell mutation and what this means for you.

Genetic mutations aren't always a bad thing. A groundbreaking new study suggests that mutations on a single gene may actually be beneficial when it comes to Alzheimer’s disease.

The study, which was published in the journal Cell Stem Cell, looked at blood stem cells' interaction with the brain, and how mutations on a single gene can protect against Alzheimer's. “We now know that these cells that circulate in the blood also have the capacity to go into the brain,” says Katherine King, MD, PhD, study co-author and professor at the Baylor College of Medicine. “That’s important in something like Alzheimer’s disease.”

Here's what the research found, plus what it suggests for the future of Alzheimer’s treatment.

Meet the experts: Clifford Segil, DO, is a neurologist at Providence Saint John’s Health Center in Santa Monica, CA; Katherine King, MD, PhD, is a study co-author and professor at the Baylor College of Medicine

What did the study find?

For the study, Dr. King and her fellow researchers looked at blood stem cells in mice and humans. They discovered that people and mice with specific blood stem cell mutations in a gene called TET2 were less likely to develop Alzheimer’s disease than those without the mutation. As a result, the researchers concluded that there appears to be a “protective effect” of this mutation.

What are blood stem cells?

Blood stem cells, a.k.a. hematopoietic stem cells, live in the bone marrow and make different types of blood cells, including red blood cells, immune cells, and platelets, Dr. King explains.

“Immune cells protect us from infections, but they have an important role in helping the body stay healthy. That includes ‘taking out the trash,’” Dr. King explains, referring to cellular waste. “Our tissues normally produce waste and sometimes get injured. We have to clear out the injured cells to make way for healthy cells.”

How are blood stem cells related to Alzheimer’s?

As you age, these blood stem cells can develop mutations. The mutations don’t usually cause issues, but sometimes they cause cells to divide more than others and create a clone. That’s called clonal hematopoiesis, and it’s been linked to a higher risk for conditions like cardiovascular disease, leukemia, stroke, and more.

But blood stem cell mutations in the TET2 gene can travel to the brain, where they may actually help clear out damaged tissue that naturally accumulates with age, Dr. King explains. “In Alzheimer’s disease, there are proteins or parts of cells that are damaged tissues that build up,” she says. “We have to get rid of them or clear them away.”

This new research essentially found that the mutated blood stem cells can go to the brain and help with the process of “clearing out the trash,” King says.

How might this discovery help create new treatments?

The discovery has opened the door for potential new treatments, although we’re not quite there yet. “Supportive cells to brain neurons may be a future potential target for a therapy in humans, as removing old damaged cells may be a reasonable way to fight aging in the brain,” says Clifford Segil, DO, a neurologist at Providence Saint John’s Health Center in Santa Monica, CA. A future treatment that’s able to help healthy cells remove old or unhealthy cells may help improve brain health, he says.

But Dr. King says this process is a little complicated. “The change in stem cells isn’t totally benign: There are risks and benefits,” she says. “The same change that may be helpful with Alzheimer’s disease is also linked with other dangerous things like heart disease and strokes.”

Dr. King says it may be possible to engineer stem cells to follow specific pathways to help enhance the function of the brain without causing risks—but that’s still TBD.