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Fergus J. Couch, PhD

Professor of Laboratory Medicine And Pathology
Zbigniew and Anna M. Scheller Professor of Medical Research
Chair, Division of Experimental Pathology and Laboratory Medicine,
Department of Laboratory Medicine and Pathology
Mayo Clinic Cancer Center
Rochester, Minnesota

Current Research

Goal: To improve risk prediction in women at high-risk of breast cancer.

Impact: Dr. Couch is conducting a series of studies to identify breast cancer predisposition genes and to estimate risk at all ages for those who have inherited mutations in these genes. His work may improve risk assessment in high-risk families and inform preventive intervention strategies.

What’s next: He and his colleagues will continue to refine breast cancer risks, resolve problematic mutations that have uncertain relevance to cancer, and identify new breast cancer genes that may account for the unexplained increased number of cancers in many families without known genetic factors.

BRCA1 and BRCA2 are the most well-known breast cancer risk genes, and women and men who inherit mutations in either gene have a significant risk of developing breast or other cancers. However, many other genes also increase the risk of breast cancer, but these are not fully understood. Dr. Couch aims to identify these genes and assess the risk they pose at various ages, which he hopes will lead to more accurate and informed risk management.

Full Research Summary

Research area: Identifying genes—beyond the well-known BRCA1 and BRCA2 genes—that increase the risk of breast cancer.

Impact: In addition to the BRCA genes, there are many other genes that when mutated predispose women and men to breast cancer. However, these are less well known, and even among those we do know, the risks of developing breast cancer at various ages are not well understood. As a result, many people at increased risk may not be identified or do not benefit from genetic testing of the known predisposition genes. Dr. Couch is conducting studies to fill in this information in order to improve risk assessment in high-risk families and spur new preventive intervention strategies.

Current investigation: He and his team have been developing estimates of cancer risks for inherited mutations found during clinical genetic testing. Through DNA sequencing, they will also identify new breast cancer genes which may be useful for identifying women at risk of developing breast cancer.

What he’s learned so far: Dr. Couch has provided the first-ever estimates of breast cancer risk for women of different races and ethnicities with inherited cancer predisposition gene mutations. Moreover, his team has shown that different types of breast cancer are caused by different genes. His team has also developed new methods to determine whether gene variants of uncertain significance are relevant to cancer risk. In preliminary studies, they have identified 21 new candidate genes which may be moderate-risk breast cancer susceptibility genes.  

What’s next: Dr. Couch and his colleagues will use the methods they have developed to determine which gene variants of uncertain significance contribute to breast cancer risk. In addition, they will continue to characterize breast cancer risk associated with variants in known cancer predisposition genes as well as the new candidate moderate-risk genes. Lastly, his team will correlate expression of specific variants with patient response to endocrine agents and chemotherapy. The insights gained from these studies will lead to more informed, accurate, and beneficial risk management and guide therapy decisions for many women at increased risk of breast cancer.


Fergus Couch is Professor and Chair of the Division of Experimental Pathology and Laboratory Medicine at the Mayo Clinic, with joint appointments in the Departments of Health Sciences Research and Biochemistry and Molecular Biology. Dr. Couch works on the genetics of breast cancer, with over 300 publications relating to the discovery and clinical characterization of inherited genetic variants in cancer susceptibility genes. He is the principal investigator of the Mayo Clinic Breast Cancer Registry and is a founder and a member of the coordinating committee of CIMBA (the consortium of investigators of modifiers of BRCA1/2) focused on identifying genetic modifiers of breast cancer risk in the BRCA1 carrier population. Similarly, he is the principal investigator of the Triple Negative Breast Cancer Consortium (TNBCC), aimed at understanding the genetic etiology of triple negative breast cancer, and is a long-term contributor to the international Breast Cancer Association Consortium (BCAC). Dr. Couch is a co-founder of the Evidence-based Network for the Interpretation of Germline Mutant Alleles (ENIGMA) consortium focused on establishing the clinical relevance of variants of uncertain significance (VUS) in BRCA1/2. Within ENIGMA he is coordinating efforts to characterize the risk and penetrance of deleterious mutations and VUS in non-BRCA1/2 predisposition genes. He has also collaborated with investigators from Memorial Sloan Kettering Cancer Center and the University of Pennsylvania to develop the Prospective Registry Of Multi-Plex Testing (PROMPT) for patients with mutations in predisposition genes. Dr. Couch is a founding member and participant in COMPLEXO, a consortium aiming to identify additional breast cancer predisposition genes.

Grid Researcher Headshot - Couch F

BCRF Investigator Since


Donor Recognition

The Ulta Beauty Award

Area(s) of Focus