In a New Approach to Fighting Disease, Helpful Genetic Mutations Are Sought
By GINA KOLATADEC. 28, 2014
Doug Whitney should have died years ago. The 65-year-old resident of Port Orchard, Wash., has a devastating gene mutation that — according to the medical literature — causes early onset Alzheimer’s disease in everyone who inherits it.
The mutation killed Mr. Whitney’smother and nine of her 13 siblings, and it killed Mr. Whitney’s older brother. Every one of them began showing symptoms when they were in their 40s. Most died by their mid-50s. In the next generation, six cousins died of early onset Alzheimer’s, and two others are in the final stages of the disease. One of his cousin’s children also has Alzheimer’s.
But Mr. Whitney has somehow escaped that fate. His memory is intact, and he has no signs of Alzheimer’s disease. Researchers want to find out why. They suspect he has another gene mutation that somehow protects him from the horrific Alzheimer’s gene mutation, or that at least substantially delays the disease’s onset.
So Mr. Whitney has become Exhibit A in a new direction in geneticsresearch. After years of looking for mutations that cause diseases, investigators are now searching for those that prevent them.
By understanding how protective mutations work, they hope to develop drugs that mimic them and protect everyone.
The new approach is turning genetics research on its head, said Eric E. Schadt, director of the Icahn Institute, a medical research institute at Mount Sinai in New York.
“Instead of trying to fix things that are broken let’s look at people where things are broken but nature finds way around it,” he explained.
In recent years, a few astounding protective gene mutations have been discovered, pretty much by accident. One prevents H.I.V. from entering cells and another enormously reduces the amount of LDL cholesterol, the dangerous kind, that people make. Both led to drugs. The AIDS drug is a mainstay of treatment, and the cholesterol drug is in the final stages of testing.
Researchers, using systematic searches of genetic databases, also found alterations in some genes that partially protect from diseases like heart disease, osteoporosis, Type 2 diabetes and Alzheimer’s.
But now some are starting a more ambitious project — a search for mutations that provide complete protection.
It may sound obvious — why not look for people who have a genetic resistance to a disease? After all, everyone knows families that never seem to get common diseases like cancer or heart disease or osteoporosis. Genes might well be involved.
But the trick is to figure out if disease resistance is from a good gene mutation or a good environment or simply good luck, defying the odds when a disease is likely but not inevitable.
And if there is a good gene mutation involved, searching for it among the 20,000 human genes can be daunting. It is easier to find mutations that cause diseases — those appear to be many times more common.
It is only now, with fast and inexpensive methods of sequencing DNA and with massive and ever-growing databases of study subjects whose genomes have been sequenced, that it has become possible to seriously contemplate a search for rarer good genes.
The unprecedented effort has barely begun. One attempt, being led by Dr. Schadt and Dr. Stephen H. Friend, director of Sage Bionetworks, a nonprofit research organization based in Seattle, began because the two scientists had become frustrated with the failures of drug development.
Dr. Friend had worked in academia — M.I.T. and Harvard — then founded a biotechnology company, Rosetta Inpharmatics, and later helped run the cancer drug discovery effort at Merck. He began each new position feeling optimistic. More and more was being discovered about disease-causing genes. “I thought we should be able to develop drugs,” he said.
But all too often disease-causing mutations destroy or disable genes, and drugs would have to restore what was lost, which can be difficult.
So Dr. Friend and Dr. Schadt decided to flip it around and search for a good gene mutation that counteracts the bad and — in an easier process — mimic that with a drug.
They gave their plan a name, The Resilience Project, and decided to search databases that held genetic and clinical information, looking for healthy people with mutations for fatal diseases that strike early in life. If the people had lived far past the age when the disease should have appeared, they assumed they might have a lucky good gene mutation that blocked the bad.
Now, a year later, “we are in this interesting place between excited and frustrated,” Dr. Friend says. They analyzed data from over 500,000 people and found 20 who seem to be protected from a fatal disease. But because of privacy issues there were no names attached to the data.
Four of the subjects are in China. Dr. Schadt and Dr. Friend are trying to find a way to contact them, but “it is very difficult,” Dr. Schadt said.
Dr. Friend and Dr. Schadt are now looking at other databases that might make it easier to contact subjects, but also decided they need to try different approaches. One will be to simply ask healthy people to let them sequence their DNA, putting out the word that they are looking for volunteers, perhaps hundreds of thousands of them. People who agreed would be contacted only if they appeared to be protected from a fatal disease.
Another is to contact researchers studying extended families with a severe genetic disease to see if they came across anyone who seemed protected. That approach appeared to be a long shot — the number of people in such studies is limited, and if there had been anyone who was protected, wouldn’t the researchers have noticed and published their story?
But when they contacted researchers at Washington University, who were studying families with a gene, presenilin, that causes early Alzheimer’s, they discovered Doug Whitney.
He certainly is unusual, researchers agree. He could, of course, still get Alzheimer’s, but it would have been substantially delayed.
Mr. Whitney had been waiting for Alzheimer’s symptoms, starting when he turned 40. He knew he had a 50-50 chance of inheriting the Alzheimer’s mutation. But year after year went by and nothing happened.
In 2011, he joined a study at Washington University in St. Louis, led by Dr. Randall Bateman, that recruited people from families with an early onset Alzheimer’s gene mutation. Mr. Whitney had finally concluded he did not have the gene mutation — he was 61, after all, and his memory and thinking were fine. On May 31, 2011, his 62nd birthday, he decided to have the genetic test. The result came back the next month. He had the gene.
But now everything has changed again. Dr. Bateman is studying Mr. Whitney. So too is Dr. Thomas Bird, a neurogeneticist at the University of Washington. Dr. Friend and Dr. Schadt have contacted him too.
Mr. Whitney is happy to help. He has just retired and when people ask what he will do now, he has a new reply: “My job is to help them figure out Alzheimer’s. I will do what I can to make it happen.”
