Joann Sweasy, PhD

Ensign Professor of Therapeutic Radiology and Professor of Genetics; Vice-Chair for Basic Research; Associate Director, Basic Science, Yale Cancer Center

Departments & Organizations

Therapeutic Radiology: Radiobiology | Sweasy Lab | Therapeutic Radiology - Research

School of Public Health: Environmental Health Sciences

Radiobiology & Radiotherapy

Status of Women in Medicine Committee (SWIM)

WHRY Pilot Project Program Investigators

Yale Cancer Center: Radiobiology & Radiotherapy

Yale Combined Program in the Biological and Biomedical Sciences (BBS): Microbiology | Molecular Cell Biology, Genetics and Development

Office of Cooperative Research


I am an expert in the genetics, cell biology, mutagenesis and biochemistry of DNA repair and cancer and have been funded continuously by the NIH since 1994.  A major focus of my laboratory is to understand how single nucleotide polymorphisms in DNA repair genes, including genes that function in homology directed repair (HDR), nonhomologous end-joining (NHEJ) and base excision repair (BER) in the germline and somatic tissues impact cancer risk and treatment. We have recently found that RAD51, DNA glycosylase, and POLB germline and somatic tumor variants exhibit functional phenotypes that lead to cellular transformation, genomic instability, and sensitivity or resistance to chemotherapies and ionizing radiation.  We have also developed methods to monitor DNA damage in tissue including the presence of single and double strand breaks that lead to PARP activation and trapping. In addition to this, I have focused on determining the roles of DNA repair in a vertebrate organism and have concentrated my studies on mouse models of DNA repair variants.  Using these models I have revealed critical roles for DNA repair in preventing the autoimmune disease of lupus.  As Associate Director for Basic Research at the Yale Comprehensive Cancer Center, I oversee several pilot and internal grant competitions, am the Principal Investigator of the American Cancer Society Institutional Research Grant, and am currently leading the development of a Translational Research Core which is designed to link patient health records to biospecimens, genomics data, and a living tumor registry. 



Education & Training

PhD Rutgers University (1989)
BA Beaver College, Biology and Chemistry (1980)
Postdoctoral Research Fellow University of Washington, Seattle, WA
Graduate Research Fellow Rutgers University,Piscataway, NJ
Senior Staff Microbiologist Merck and Company, Rahway, NJ
Undergraduate Research Assistant, Beaver College, Glenside, PA
Postdoctoral Fellow University of Washington, Seattle, WA

Honors & Recognition

  • Argall and Anna Hull Award

  • American Cancer Society Junior Faculty Research Award

  • Donaghue Investigator Award

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