The man must have developed Alzheimer’s in his early 40s — he had a genetic mutation that contained it, or so it seemed. Scans of his brain revealed severe atrophy and hallmarks of the disease: rough, hard plaques of amyloid and spaghetti-like tangles of tau proteins. But the fatal brain disease did not appear until the man was 67 years old.
Now extensive research efforts have discovered the reason. The man was protected because another mutation in a different gene prevented the disease from entering the inner spinal cortex. This small region of the brain is a hub for neurons involved in memory, object recognition, navigation and time perception. There, scientists believe, Alzheimer’s disease begins.
a paper The discovery was published Monday in the journal Nature Medicine.
Why it matters: A possible course of treatment.
More than six million People in the United States suffer from Alzheimer’s disease, a disease that is notoriously difficult to treat. However, there was a man with a mutation that causes the most severe and rapidly progressive form of Alzheimer’s disease. And his illness was delayed by two decades. If a drug can do what the mutation did, causing most people to develop Alzheimer’s disease very late in life, the result could be transformative.
Dr Joseph F. said: Arboleda-Velasquez, a cell biologist at Massachusetts Eye and Ear in Boston and a member of the research team: “This really holds the secret for the next generation of therapies.” Dr. Arboleda-Rodriguez is a co-founder of a biotechnology company looking to create drugs that could work in this research.
It is not excluded, said Dr. Diego Sepúlveda Valla, a neurologist at the University of Hamburg in Germany and a member of the research team. The mutation results in a robust version of the protein, Reelin, in the inner spinal cortex. The super-strong Reelin ultimately prevents tangled strands of tau proteins from sticking together and forming the structures that characterize Alzheimer’s disease.
The idea, he said, is to “go in with an injection and treat only one area” of the brain.
But this type of treatment will be discontinued in the future and may no longer be possible, warned Dr. Thomas Byrd, professor emeritus of neuroscience and clinical genetics at the University of Washington. Dr. Baird was not involved in the study.
The entorhinal cortex is a very small area. “We don’t know what kind of damage you might do, by sticking needles and dropping chemicals,” he said.
Background: New insight from ongoing research.
The man researchers call “resilient” to Alzheimer’s disease was part of a decades-long study 6,000 people live in Colombia People with a genetic mutation that causes Alzheimer’s disease in middle age. Many agreed to genetic testing, brain scans and, after their death, brain autopsies.
A few years ago, the same research group in the current study I identified a woman which was also protected against Alzheimer’s disease. But in her case, the flexibility was caused by a mutation in a different gene, APOE. Instead of lacking tau masses in one small area of her brain, they were missing in her entire brain.
But the researchers say they believe the two patients reveal a new way to treat Alzheimer’s disease. The two mutated genes interrupt a molecular chain of events required for the assembly of tau in the brain.
What’s next: Further research and combined therapies.
The hypothesis that a drug can protect the entorhinal cortex of other patients requires further research. Animal studies are already underway, Dr. Arboleda Velazquez said. Members of the group inject the mutant form of Reelin into the same part of the brain in mice susceptible to an Alzheimer’s-like disease to see if it is protective.
The future may include combination therapies, said Dr. Eric Riemann, a member of the research team, executive director of the Banner Alzheimer’s Institute in Phoenix and a paid consultant to several drug companies. The hope is to prevent the buildup of amyloid and tau and delay Alzheimer’s disease in susceptible people so long that it is no longer a problem.