09 May Marshfield study mixes DNA into electronic medical record to screen for Alzheimer's
Marshfield Clinic has embarked on a novel project to match genetic information from Alzheimer’s patients with environmental factors that may contribute to the disease.
The two-year project is the first to tap the more than 18,000 DNA samples Marshfield Clinic has gathered for its Personalized Medicine Research Project, one of the nation’s largest bio-banking efforts. Capitalizing on Marshfield’s extensive database of electronic medical records, the project aims to develop a set of genetic markers that would allow doctors to screen a person early in life to determine their risk for the disease.
The study will focus on four specific genes and their connection to the disease.
“So now that [we] have their DNA, we have a complete medical record,” said Nader Ghebranious, Ph.D., the primary investigator for the project and director of the clinic’s Molecular Diagnostics Laboratory. “We know exactly the medication they have been taking [and] what diseases they have been diagnosed for. We have also some environmental factors. Now we can do genetic analysis and look at genes and the DNA with the phenotypes we have.”
No other project to date has made that critical phenotype-genotype link, according to Marshfield epidemiologist Catherine McCarty, who leads the Personalized Medicine Research Project and is a co-investigator for the Alzheimer’s project.
“From my perspective as an epidemiologist, it’s really exciting because we’re not looking at just environmental factors or risk factors or exposures throughout our lives, or just the genetics, but looking at the two together,” McCarty said. “I don’t know of anybody who’s done that thus far.”
The study is focusing on patients who are at least 70. Researchers will study 150 people who have Alzheimer’s disease and about 300 people who do not. They will be re-contacting people they believe do not have Alzheimer’s to confirm that, doing what are called mini mental exams, basically short lists of questions that are commonly used in clinical settings to confirm that the person truly does not have the disease.
“It might be that someone already is exhibiting some of the earlier signs but hasn’t come in yet,” McCarty said. “It’s important for our study to very carefully decide who does and does not have Alzheimer’s disease.”
Other co-investigators for the project are Susan Mickel, a neurologist and Alzheimer’s specialist at Marshfield, and Russell Wilke, Marshfield’s head of pharmacogenetics. Wilke will head up the project’s study of statins, which are one of the most commonly used medications to lower cholesterol and may actually protect a person from developing Alzheimer’s. The project also will study the effects of smoking on the brain.
“Some of it could be related to a lifestyle change,” Ghebranious said. “Although there hasn’t been a cure for Alzheimer’s disease yet, there is a lot of research going on. Hopefully in five to 10 years, we would have a cure. Hopefully there will be some medications. It is known that high cholesterol could be a risk factor. It’s not definite, but there are some risks that are known, and those things could be changed just by changing lifestyle.
“The other thing that we could learn from this type of study is, now that we know what genes confer a risk to Alzheimer’s disease, we could go back and try to design [therapies] that could target those particular genes – for instance, to prevent their bad effect,” he added. “So not only could we diagnose patients, but maybe it could open a door for research on those genes to design drugs that would target those malfunctioning genes. So it’s very important to be able to find out this information.”
Right now there is no primary prevention strategy for Alzheimer’s. This latest project may pave the way for just that.
“Say we find there’s an interaction between smoking and statins and genetics,” McCarty theorized. “Maybe we’ll say ‘A-ha! Somebody with this genetic makeup might be best-off starting to take a statin when they’re 50, and that will either delay or prevent the onset of the disease.”