The woman’s genetic profile showed she would develop Alzheimer’s by the time she turned 50.
She, like thousands of her relatives, going back generations, was born with a gene mutation that causes people to begin having memory and thinking problems in their 40s and deteriorate rapidly toward death around age 60.
But remarkably, she experienced no cognitive decline at all until her 70s, nearly three decades later than expected.
How did that happen? New research provides an answer, one that experts say could change the scientific understanding of Alzheimer’s disease and inspire new ideas about how to prevent and treat it.
In a study published Monday in the journal Nature Medicine, researchers say the woman, whose name they withheld to protect her privacy, has another mutation that has protected her from dementia even though her brain has developed a major neurological feature of Alzheimer’s disease.
This ultra rare mutation appears to help stave off the disease by minimizing the binding of a particular sugar compound to an important gene. That finding suggests that treatments could be developed to give other people that same protective mechanism.
“I’m very excited to see this new study come out — the impact is dramatic,” said Dr. Yadong Huang, a senior investigator at Gladstone Institutes, who was not involved in the research. “For both research and therapeutic development, this new finding is very important.”