These families help scientists find Alzheimer’s treatments. Their network is at risk : NPR

SCOTT DETROW, HOST:

Some of the most important research on Alzheimer’s disease relies on altruism.

JUNE WARD: It’s not for us, but it’s for my sister’s children and their children so that they don’t have the same choice.

DETROW: NPR’s Jon Hamilton reports on an international network of families with an inherited form of Alzheimer’s disease. The network has enabled scientists to make key discoveries, but it faces an uncertain future due to cuts in federal funding.

JON HAMILTON, BYLINE: Families carry rare genetic mutations that cause Alzheimer’s disease in middle age or even earlier. June Ward and her sisters discovered that a cousin had started having memory problems in her 50s and decided to have her genes tested.

WARD: It was always in our peripheral vision and finding out that our cousin had the genetic mutation was right in front of our face, so we knew what it was and what the chances were that we would be personally affected by the disease.

HAMILTON: Those odds – 50/50 for each sibling. Ward and her sisters wanted to do something, so they joined the Dominantly Inherited Alzheimer’s Network, or DIAN. It involves more than 200 families in 10 countries.

WARD: And now we’re doing what we can do, which is participating in drug trials and trying to take every step possible for a better future.

HAMILTON: DIAN is led by WashU Medicine in St. Louis. Dr. Randall Bateman, co-director of the network, says DIAN families provide a unique window into Alzheimer’s disease.

RANDALL BATEMAN: These families carrying these mutations are still the only population in the world where we not only have the certainty of knowing if they will get it, but when they will get it.

HAMILTON: If a family member inherits a mutation from either parent, dementia is almost inevitable. The specific mutation determines whether symptoms appear in your 30s or not before your 60s. Bateman began studying affected families in the early 2000s. He was trying to understand what caused the amyloid protein to appear in the brains of people with Alzheimer’s disease.

BATEMAN: And it was clear to me that these people with these mutations could really answer that question.

HAMILTON: But the mutations are so rare that no research center had enough family members for a large-scale study. So in 2008, the National Institutes of Health began funding DIAN to create a common group of participants. Bateman says the multi-million dollar investment has paid off. For example, he says, it was the brain scans of members of the DIAN family that allowed scientists to discover how Alzheimer’s disease begins.

BATEMAN: Before the first memory loss is noticed, there is this 20-year period where changes occur in the brain, and they lead to the appearance of the first symptoms that then lead to dementia and disability and ultimately death.

HAMILTON: In 2012, DIAN added a clinical trial unit for potential Alzheimer’s disease drugs. This is a partnership with the Alzheimer’s Association and pharmaceutical companies. Bateman says this gave companies a way to test their drugs on people destined to contract the disease.

BATEMAN: Our ability to determine what the effects of these treatments are really relies on that certainty.

HAMILTON: Early studies in DIAN families showed that certain medications could reduce amyloid in the brain, and a study in 2025 suggested it could delay symptoms of the disease. DIAN scientists also discovered a few people who carried a mutation but seemed protected from dementia. One of them is Doug Whitney, who spoke with NPR last year.

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DOUG WHITNEY: Well, I’m 75 years old and I think I function pretty well. I still don’t have any symptoms of Alzheimer’s disease.

HAMILTON: Scientists studied Whitney to understand why, and he was eager to help them.

WHITNEY: I guess I’m a little special (laughs). But you know, I told the researchers that if you need me, I’ll be there.

HAMILTON: Some members of the DIAN family do more than just participate in research studies. Take Lindsay (ph), who asked that we use only her first name in order to candidly discuss her family’s medical history. Lindsay’s father was diagnosed with Alzheimer’s disease when he was 48 and she was 18.

LINDSAY: Seeing the strongest, smartest person in your life suddenly be overcome by something so terrible to the point where they can no longer speak, to the point where they no longer know who you are – there are no words to describe what that experience is like.

HAMILTON: Lindsay responded by diving into science.

LINDSAY: I went to our local library and checked out all the books about Alzheimer’s because I thought there must be something we can do.

HAMILTON: There wasn’t. Lindsay began taking science classes in college. Then she joined DIAN, even though it meant several days of uncomfortable tests.

LINDSAY: I had a spinal tap. I had an MRI. I had a PET scan. I got a lot of blood. I did cognitive tests, neurological tests – the whole nine yards.

HAMILTON: Including a genetic test, though, at the time, Lindsay chose not to see the result. She just continued to study.

LINDSAY: Well, now I have a Ph.D. in neuroscience and I work in a laboratory on Alzheimer’s disease.

HAMILTON: Lindsay finally learned she didn’t have the early-onset Alzheimer’s mutation. Yet she continues to attend the annual DIAN Families Meeting and help run a nonprofit organization for these families called Youngtimers.

Dr. Tammie Benzinger, a radiologist at WashU Medicine, says DIAN offers benefits to people who join the network. They have access to world-class experts and meet other members of affected families. But participants also undergo extensive and repeated testing, and Benzinger says those who volunteer for drug trials run the risk of side effects like brain swelling or bleeding.

TAMMIE BENZINGER: It’s an incredible contribution, especially when you think about the fact that these are young people. They still have work to do. They have young children.

HAMILTON: Benzinger says the DIAN families helped make amyloid drugs a reality. Two of them are now on the market and, according to her, the DIAN network has played an important role in evaluating the side effects of this class of drugs.

BENZINGER: What we’ve seen with amyloid therapies is the importance of this DIAN cohort. And for the next therapies to see the light of day, I think we really need this network to continue to function.

HAMILTON: It’s not a certainty. After the Trump administration took power in 2025, WashU was asked to reduce its DIAN funding request by more than a third. Benzinger says deeper cuts could cause significant damage.

BENZINGER: The network built, the years spent in training and relationships – without funding, all of that would collapse.

HAMILTON: Right now, DIAN is getting by on temporary funding from the NIH. That money came after Lindsay and other family members joined the network.

LINDSAY: We got 600 signatures in three days that were then sent to the NIH advisory board.

HAMILTON: Lindsay is encouraged that Congress continues to vote in favor of Alzheimer’s research. Despite this, it is unclear what will happen to the federal grants that supported DIAN. Lindsay says she’s trying to stay optimistic.

LINDSAY: I’m still that naive 18-year-old girl who thinks she can cure her father. Obviously I didn’t, otherwise he would be sitting next to me right now.

HAMILTON: A cure remains far away, but Lindsay says there is growing evidence that amyloid medications, if given early enough, can delay disease symptoms in people with the mutation.

LINDSAY: I 100% believe that the first Alzheimer’s survivor will come from this community.

HAMILTON: Assuming the community itself can remain intact. Jon Hamilton, NPR News.

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