A Washington man appeared destined to develop Alzheimer’s disease.

But against all genetic odds, he has eluded the common dementia for decades. Researchers at Washington University School of Medicine in St. Louis recently published a study. It focuses on Doug Whitney, 76, who lives near Seattle.

He has a rare inherited genetic mutation in the presenilin 2 gene. This virtually guarantees early-onset Alzheimer’s.

All of Whitney’s family members who inherited the gene have experienced cognitive decline. This started in their early 50s or sooner. Washington University provided this information in a press release.

Whitney shows no signs of mental decline.

WashU researchers wondered if the reason for his continued cognitive health could help protect others. In a study published in the journal Nature Medicine, researchers analyzed his genetic data and brain scans.

They identified changes in genes and proteins that could explain how he has defied the odds. The researchers also discovered that Whitney’s brain had virtually no buildup of tau. Tau is the hallmark protein that signals the onset of cognitive decline.

“These extensive studies indicate a remarkable resistance to tau pathology and neurodegeneration.”

Senior study author Randall J. Bateman said this in the press release. He is the Charles F. and Joanne Knight Distinguished Professor of Neurology at WashU Medicine.

Whitney first came to WashU in 2011. His cousin urged him to participate in a study. The study focused on families with inherited forms of Alzheimer’s. Many of his relatives had developed early-onset disease.

At the time, Whitney believed he did not have the gene.

“He actually was able to escape the expected course of the disease.”

Whitney’s mother was one of 14 children. Nine of them had the Alzheimer’s gene. Ten of them died before they were 60.

Whitney’s own brother developed the disease before dying at age 55.

“I was 61 at the time — well past the age where it should have onset. But they tested me, and lo and behold, I did have the gene. I was amazed.”

Whitney told Fox News Digital this during an on-camera interview.

The researchers were just as confounded, Whitney recalled. They tested him three times to make sure there wasn’t some slip-up.

“But it’s true. I had the gene. And now I’m 76 years old and still haven’t had any symptoms.”

Jorge Llibre-Guerra is an assistant professor of neurology. He is a co-first author of the study. He said it was a big surprise to learn Whitney was a carrier of the genetic mutation.

The mutation is officially known as an exceptional resilience mutation carrier.

“He actually was able to escape the expected course of the disease.”

Now in this most recent study, WashU researchers aimed to explore potential reasons. They wanted to understand Whitney’s absence of Alzheimer’s.

“If we are able to uncover the mechanism behind this resilience, we could try to replicate it with a targeted therapy designed to delay or prevent the onset of Alzheimer’s, leveraging the same protective factors that have kept Mr. Whitney from developing this disease to benefit others.”

Those who have the PSEN2 mutation tend to have an over-production of amyloid protein. This builds up in the brain during the first stage of Alzheimer’s. In the second stage, as symptoms of cognitive decline begin, there is typically a buildup of tau protein.

In Whitney’s case, brain scans showed a significant accumulation of amyloid. But there was almost a complete absence of tau.

One theory for how Whitney may have escaped his genetic fate stems from his time in the Navy. When researchers analyzed Whitney’s cerebrospinal fluid, they found a significantly higher-than-normal level of heat shock proteins.

These are protective molecules that cells produce when they’re under stress. This includes high heat exposure.

During his many years working as a shipboard mechanic in the Navy, Whitney was exposed to high temperatures. These exposures lasted for extended periods of time.

“In the engine room of ships, the temperatures … would range from 100 to 110 degrees, for four hours at a time. They concluded that possibly there was some gene or protein that could mutate and protect me genetically from the disease.”

“We don’t yet understand how or if heat shock proteins may be mediating the effect. However, in this case, they may be involved in preventing aggregation and misfolding of tau proteins, but we do not know for sure.”

The research was supported in part by the Dominantly Inherited Alzheimer Network. The National Institute on Aging and the Alzheimer’s Association also provided support.

To help him stay sharp, Whitney often does crossword puzzles and Sudoku. He does these activities with his wife.

“I think I’m pretty healthy at 76. I’m pretty active, and I hardly have any medications to take.”

For those experiencing symptoms, Whitney recommends contacting the Alzheimer’s Association.

“Get into research as soon as possible — the earlier you get in, the better chance you have. Don’t give up. Nobody’s alone out there anymore. There are lots of people waiting to help you.”

Whitney said he is optimistic about the future of Alzheimer’s treatment.

“Looking at the advances they’ve made over the last 14 years — it’s amazing. It’s imperative that we keep going.”

Llibre-Guerra said he’s hopeful the insights from Whitney’s case will spark broader studies. These would be in both people and animals. They would aim at uncovering the biological secrets behind his resistance.

“We have made all of the data we have available, as well as the tissue samples. If researchers want to request those to do additional analysis, that’s something we would welcome.”

Whitney said he is committed to helping advance Alzheimer’s research. His wife refers to it as his third career.

“It’s become my calling. When we go for testing, it’s a pretty rigorous day, but after 14 years, I’m used to it now, so that’s not a concern.”

“As long as they need me, I’ll be here. I’m in it for the long haul.”