Deyana Lewis, Ph.D., M.P.H.

Dr. Deyana Lewis

IRTA Postdoctoral Fellow
National Human Genome Research Institute

Project Title: “Whole Exome Sequencing of High Risk African American Prostate Cancer Families”

Prostate cancer (PCa) is the second leading cause of cancer deaths among American men. However, African American (AA) men have the highest rates of PCa—more than any other ethnic group in the United States—and are more than twice as likely as men with European ancestry (EA) to die of the disease. Although socioeconomic factors contribute to the disparity of the disease, the impact of genetic factors plays a considerable role that has been long recognized and studied. Early large genome-wide association studies that identified variants for PCa focused mainly on European populations. More recent studies in non-European cohorts suggest that underlying risk variants may be more common in AA men than EA men. So far, research has identified only one hereditary PCa (HPC) susceptibility gene in EA men, and confirmatory studies have produced mixed results. Additional studies of minority groups, especially AAs, will be critical for determining whether and how different variations in single nucleotide polymorphisms (SNPs) play roles in PCa in the high-risk AA population.

Whole exome sequencing (WES) of HPC families can help identify rare susceptibility variants that more often affect AAs. The researchers have WES data on EA men with HPC from previous studies and from members of families affected by HPC, but they have little data from AA men. The researchers will sequence exomes of additional members of AA families whose data has been most informative. The researchers will merge data from these family members and from previous studies to achieve larger sample size and compare findings with previous studies to identify genetic variations that contribute to the aggressiveness of PCa in AA men and with findings on EAs in previous studies. This study is poised to increase the amount of genetic data available from AA families and our understanding of an important health disparity and may support the case for sequencing more members of high-risk AA families to gather data that could improve PCa screening.