Overview

Medical genomics is the correlation of individual differences in gene structure and function with the characteristics of disease and response to treatment. It promises to fundamentally change the practice of medicine by:

• Facilitating the identification of new genes with disease relevance.
• Providing better characterization of subcategories of disease.
• Creating the potential for individualized drug therapies. Not all drugs work equally well for all patients.

At best, we only understand the function of about half of our 30,000-50,000 genes. As we begin to define the functions of the remaining genes, there is tremendous potential for understanding human disease at a molecular level. Andre Terzic, M.D., Ph.D., , has just succeeded in identifying a gene that is responsible for a heart condition called dilated cardiomyopathy. This is a critical first step towards defining new, more effective approaches to the care of the patient.

The ability to simultaneously monitor the expression of all human genes in small diagnostic tissue samples has led to significant improvements in our ability to distinguish patients with more or less severe forms of many diseases. Diane Jelinek, Ph.D. is using microarrays ("gene chips") to make significant progress in identifying functionally distinct categories of human leukemias. The more accurately we can classify diseases, the easier it becomes to select the best treatment.

The emerging field of pharmacogenomics is already beginning to allow physicians to identify which drugs are the most appropriate for a given patient. Richard Weinshilboum, M.D., has identified patients that have gene sequence differences in a drug metabolizing enzyme. Patients who have the variant form of the gene have toxic reactions to standard doses of anticancer drugs. In keeping with Mayo's primary value that "the needs of the patient come first", the institution has begun a long-term program to ensure that Mayo can sustain a leadership position in medical genomics.