June Ward (right) — pictured with her sisters Susie Gilliam (center) and Karen Douthitt (left) — carries a rare gene mutation that virtually guarantees she will get Alzheimer’s in the next few years. She is part of a network of more than 200 families with these kinds of gene mutations who have volunteered as research subjects over the past two decades.
Juan Diego Reyes for NPR
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Juan Diego Reyes for NPR
Critical studies on potential Alzheimer’s treatments depend heavily on participants who might not benefit directly. June Ward, 64, possessing a rare gene mutation that almost certainly leads to Alzheimer’s, is part of this group. She explains, “It’s not for us. It’s for my sister’s children and their children, so that they won’t have the same ‘nothing’ to choose from.”
Ward is involved with the Dominantly Inherited Alzheimer Network (DIAN), which encompasses over 200 families across 18 countries who carry gene mutations causing symptoms to manifest in middle age or earlier.
For more than two decades, these families have willingly participated in research, enabling scientists to uncover crucial insights into the onset of Alzheimer’s and the potential of certain drugs to slow its progression.
Despite its significant contributions, DIAN, managed by WashU Medicine in St. Louis, faces a precarious future due to federal funding cuts and delays. Currently, the program is operating only its essential functions while awaiting crucial grants from the National Institutes of Health (NIH).
“The network that’s been built up, the years that have gone into the training and the relationships — without funding, all of that would fall apart,” says Dr. Tammie Benzinger, a professor of radiology at WashU who oversees brain imaging for DIAN participants.
Families riddled with dementia
DIAN comprises families like Ward’s who carry one of three different gene mutations that can lead to Alzheimer’s symptoms manifesting in a person’s 40s or 50s. Each child with a parent having the mutation has a 50% chance of inheriting it, and those who do are almost certain to develop Alzheimer’s before 65.
This high risk makes these families invaluable to Alzheimer’s research, notes Dr. Randall Bateman, a professor of neurology at WashU Medicine and co-director of DIAN. “They represent the only population in the world where we not only have certainty about whether they will get it, but when they will get it,” he says.
Bateman began his studies on affected families in the early 2000s, aiming to understand why the protein amyloid appears in the brains of Alzheimer’s patients. “It was clear to me that people with these mutations could answer that question,” he says.
Given the rarity of these mutations, no single research center had enough family members for a large study. Thus, in 2008, the NIH began funding DIAN to establish an international registry.
A window on Alzheimer’s
The investment in DIAN has proven fruitful, according to Bateman. Brain scans of DIAN family members have helped identify how Alzheimer’s begins, revealing a 20-year period of changes in the brain before memory loss is noticed.
In 2012, DIAN joined forces with the Alzheimer’s Association and pharmaceutical companies to form its clinical trials unit, DIAN-TU. Early trials demonstrated that certain drugs could reduce amyloid plaques associated with Alzheimer’s. A study in 2025 suggested that early reduction of amyloid could delay symptoms in those with a mutation.
Additionally, DIAN has uncovered instances where individuals with gene mutations expected to lead to Alzheimer’s do not develop the disease. Understanding this phenomenon could lead to treatments for others at high risk.
DIAN families, by testing experimental amyloid drugs, have paved the way for lecanemab and donanemab, two amyloid drugs now available. Recently, the network has helped in assessing the drugs’ side effects, such as brain swelling and bleeding.
“What we’ve seen with the amyloid therapies is how important this DIAN cohort is,” Benzinger says.
A diagnosis, then a career
Many DIAN family members go beyond participating in research studies. Take Lindsay, for example, who prefers to use only her first name to discuss her family’s medical history. Her father was diagnosed with Alzheimer’s at 48 when she was 18, prompting her to delve into brain science. “I checked out every single book on Alzheimer’s disease,” she says. “I was like, there’s got to be something we can do.”
Despite no immediate solutions, Lindsay pursued science in college and joined DIAN, undergoing several uncomfortable tests. Although she later learned she did not carry the mutation, she continues to engage with the DIAN community and co-manages a nonprofit called Youngtimers. She also holds a Ph.D. in neuroscience and works in an Alzheimer’s lab at a major university.
An uncertain future
Like many DIAN members, Lindsay worries about the network’s funding, mainly sourced from the NIH’s National Institute on Aging. When the second Trump administration began in 2025, DIAN leaders were in the process of renewing the main grant. The new administration, focused on reducing research funding, rejected the application that would have provided $13 million in its first year.
This led Lindsay and others to petition the NIH to reconsider, gathering 600 signatures in three days. Ultimately, the NIH offered about $8 million in bridge funding, falling short of DIAN’s request. Additionally, the government halted funding for DIAN’s international sites, now temporarily supported by the Alzheimer’s Association.
Despite Congress approving a $100 million increase for Alzheimer’s and dementia research in February, DIAN’s future remains uncertain. Grant reviews are delayed amid government shutdowns and changes in scientific leadership, with a critical review postponed to May, just weeks before bridge funding ends.
Lindsay remains hopeful, saying, “I’m still that naive 18-year-old girl thinking that she can cure her dad.” She believes that research on amyloid drugs delaying Alzheimer’s in DIAN participants is promising. “I 100% believe that the first Alzheimer’s survivor will be from this community,” she says, stressing the importance of the network’s continued existence.
