Article originally posted on Discovery's Edge.
Genetic research first intrigued pharmacologist Richard Weinshilboum, M.D., of Mayo Clinic in Rochester, Minn., more than 30 years ago, when he began painstaking biochemistry techniques in his Pharmacogenomics Laboratory. As Dr. Weinshilboum's research team studied enzymes involved in eliminating neurotransmitters, they discovered a related enzyme, known as TPMT, that eliminated a particular type of toxicity from the body after drug therapy for certain leukemia patients. Because 1 in 300 children with leukemia had adverse reactions to the drug therapy, Dr. Weinshilboum was curious whether variations in enzyme levels based on each child's genes played a role in the side effects.
At Mayo Clinic, genomic, or individualized, medicine is providing a wide range of therapies that are tailored to each person's genes. It's no small feat. Despite the speed of today's sequencing methods, the amount of data in a genome is staggering: 3.2 billion chromosomal base pairs. About 2 percent of those are known as the exome and currently considered most relevant to disease processes.
"We recognized, with these developments and Mayo's infrastructure, that we had the opportunity and the obligation to bring this incredible tool to patient care," says Gianrico Farrugia, M.D., director of Mayo Clinic's Center for Individualized Medicine.
Individualized medicine at Mayo Clinic begins with careful sequencing of the relevant section of the genome in the Medical Genome Facility, led by genetics researcher Eric D. Wieben, Ph.D. Mayo Clinic has developed the infrastructure and the necessary staff of bioinformaticians, biostatisticians and computer scientists, led by Jean-Pierre A. Kocher, Ph.D., chair of the Division of Biomedical Statistics and Informatics. They perform the weeks long, highly complex stage of sorting the data, constructing an individual's genome from the information and then comparing it to a standard genome in order to isolate key areas that differ.
In those genetic variants lie the clues to how to approach treatment. This happens in Mayo Clinic's Individualized Medicine Clinic, which takes referrals for difficult-to-treat cancer cases and other hard-to-diagnose conditions that may have a genetic origin.
This year, the Center for Individualized Medicine is launching a study for prostate cancer that is similar to the BEAUTY Project. In another project, researchers will look at the gene CYP2C19 in 6,000 patients from institutions around the world to determine whether it's involved in enabling cardiovascular patients to metabolize the anti-clotting drug clopidogrel (Plavix). The findings may alter treatment for thousands of patients now receiving stents. October 2013 marked the first anniversary of the Individualized Medicine Clinic, which has now seen more than 60 patients. "There are now more than 4,000 conditions that we can look for simultaneously," says Matthew J. Ferber, Ph.D., an expert in next-generation sequencing at Mayo Clinic.
"These are patients who are finally getting an answer, which can mean an enormous amount to them and their families." And it doesn't stop there. Dr. Farrugia says that the uses of genomic medicine will continue to expand. "Mayo Clinic entered the field in a characteristically careful and thoughtful way about how the science could be of best use to patients," Dr. Farrugia says. "But we're here, and it's happening. It's our responsibility to make sure that this transforms the practice of medicine."
Source: Discovery's Edge.