Dr. Stephen Thibodeau is a Professor of Laboratory Medicine, Mayo Clinic College of Medicine and a Co-director of Molecular Genetics. In addition, he is also a member of the division of Medical Genetics.

Dr. Thibodeau's laboratory has two major areas of research. The first is to identify both high and low penetrant susceptibility genes for prostate cancer. One approach used in our laboratory involves the use of genetic linkage analysis. We have now completed several genome wide scan on a large number of families that segregate for familial prostate cancer in order to identify regions of interest. Several regions demonstrating significant evidence of linkage have been identified. In addition to fine mapping studies, we are also attempting to clone and characterize susceptibility gene(s) that have been localized to these regions. Finally, we are also performing gene association studies on a variety of candidate genes, including those involved in the androgen biosynthetic pathway. These studies are performed on familial and sporadic cases as well as a group of population based controls.

The second area of interest is to characterize the molecular genetic changes that occur in both sporadic and familial colorectal cancer (primarily HNPCC). Colon cancer results from various genetic changes at a number of different loci, including both dominant and recessive acting tumor suppressor genes. Additionally, the molecular events leading to cancer in patients having familiar colorectal cancer may share some common features to those patients having sporadic colorectal cancer. For HNPCC, abnormalities in a number of genes involved in DNA mismatch repair have been identified. Our long-term goal is to understand which DNA mismatch genes are involved, the types of mutations involved, the timing and sequence of these molecular changes, and their clinical significance. Other studies that are actively in progress include the identification and characterization of genes that are up and down regulated in colorectal cancer and their clinical significance.