Actually, more than a few are needed. Officials overseeing health care for the nation's veterans are undertaking what may be the largest effort of its kind in the nation, to collect medical records and blood samples from a million former service members for a bank of genetic information.
The idea is to give researchers enough DNA and other data to link specific genes to mental and physical maladies, from post-traumatic stress disorder to heart disease, and eventually develop new preventive measures or treatments.
"We did tell them that this may not benefit them directly," said Dr. Joel Kupersmith, the VA's chief research and development officer. "But vets are very altruistic people and they're likely to help if you tell them it will benefit someone else."
Kupersmith said researchers have long seen the potential at the VA because the system has 8 million enrollees of various ages and ethnicities with most every kind of age-, health- and service-related disorder. All have an electronic medical record stretching up to 15 years. The only shortcoming is the number of women — just over 6 percent of the system overall, and 13 percent of those actively serving in Iraq and Afghanistan.
Already, almost 51,000 men and women have agreed to participate since requests began going out by mail at the end of last year. They will visit one of 40 centers, including Baltimore, and almost half have already come in to answer questions and have blood drawn. The goal is to sign on the entire million in five to seven years, though studies will launch more immediately.
Among the early volunteers is Aaron Franz, 27, who left the Air Force in 2008 and now lives in Baltimore.
"I'm pretty scientifically minded," he said. "I'm very interested in the science of genetics and medicine. And I have a bit of service instinct. Donating a sample of blood is probably one of the easiest ways I can think to advance modern medicine."
Kupersmith said most research in the past hasn't been able to cobble so many people together. A well-known study led by the National Heart, Lung and Blood Institute that helped determine heart disease risk factors, for example, recruited about 5,000 people in 1948. The grandchildren of original participants of the "Framingham study," are now being studied for genetic traits.
"Imagine having a pool of million people," said Kupersmith, adding that already researchers are pitching studies to VA officials about post-traumatic stress disorder, schizophrenia and bi-polar disorder and amyotrophic lateral sclerosis, known as Lou Gehrig's disease.
The veterans' personal information will be kept confidential and they will have the option to participate in individual studies, which would likely require additional questions.
While the findings will benefit society as a whole as researchers build on each other's work, for now only those with a VA affiliation will be able to tap the databank. Many of the thousands with privileges will likely partner with outside scientists who are experts in their field, though.
Heading up the Baltimore region's effort to sign up 25,000 veterans is Dr. Alan Shuldiner, who is associate dean for personalized and genomic medicine in the University of Maryland's School of Medicine, as well as a VA physician and researcher.
Shuldiner also expects to continue his own studies. He's been involved with genomics research for more than 20 years, including work he's done to discover gene variations for diabetes, heart and bone disease and other maladies in the Amish in the Lancaster, Pa., area.
He said many discoveries of genes that make people more susceptible or immune to disease have been made in the past five years, but they've been slow to translate into therapies. Known gene variations don't always substantially increase risk, and when they do there aren't always obvious remedies such as diet or drugs. The databank could accelerate the discoveries and their uses, he said.
He expects to use the databank specifically to study genes that may determine who benefits and who is harmed by certain medications. Using other subjects, he and fellow Maryland researchers already have worked on a test for a genetic variation that determines how well patients will respond to Plavix, a drug commonly used to prevent heart attacks and strokes. A third of patients carry a gene variation that calls for an alternative drug.
Shuldiner said he's found that local veterans are eager to help solve the mysteries. Already, 160 people have signed up in Baltimore, including Franz, a math student at Baltimore City Community College.
Franz said the questionnaire took less than 20 minutes. And he hopes his effort helps doctors treat those who become sick — and understand those who don't — after exposure to the mental and physical hazards of war.
He'd like researchers to come up with cures and prevention methods for those with diabetes, which afflicted his mother from childhood. He also has a brother with schizophrenia and several relatives with hypertension.
"You've got a million people you can sample from," he said. "Maybe you've got enough where you can start seeing all these things they have in common, a couple of genes that for some reason are active or inactive in making you more susceptible or immune."
That's the kind of thing Dan Arking is looking at now, without the use of the giant VA database. He's an associate professor in the McKusick-Nathans Institute of Genetic Medicine in Johns Hopkins University School of Medicine.
He said treatment and prevention might be a ways off for many diseases, but there is a lot of ongoing research that can benefit from the DNA of Franz and his fellow veterans.
Typically, large studies now involve groups of about 10,000 to 15,000 pooled from 10 to 20 sources. He's seen other countries attempt to create such large databases as the VA, but this is the largest he knows of in the United States.
Arking said that in addition to common diseases, the databank will be useful for rare ones because it's often tough to find enough people to study.
Limiting the databank to VA-affiliated researchers is a drawback for scientists like Arking, who has no relationship with the veterans department but has developed novel methodology and tools to study diseases —in his case autism and sudden cardiac death. He hopes the VA makes it easy to identify and partner with the proper researchers.
For example, Arking and his colleagues have identified some genes related to sudden cardiac death, which kills up to 250,000 people a year and generally has no obvious warning signs. But if all the right variants can be identified for those most likely to die, doctors can single them out for an expensive implanted defibrillator.
"Prevention in this case is major surgery, so we need to do a better job of risk assessment before we intervene," he said.
He added: "It's an exciting time to be doing genomic research. If everything comes together with the databank, there will be an incredible amount of new discoveries to come out of this."
Vets who would like to volunteer, can go to http://www.research.va.gov/mvp/ for more information or call 866-441-6075.