In almost all countries with more than one racial/ethnic group, men of European descent are at higher risk of testicular germ cell tumors (TGCT) than are men of non-European descent, particularly men of African descent. Men of European ancestry in the U.S. have incidence rates of TGCT that are approximately seven times higher than incidence rates among African-American men. Whether the disparity is due to variability of environmental exposures or genetic differences, or a combination of the two, is not clear. However, the varying risks of different racial/ethnic groups living in one country suggest that genetic susceptibility may play a role. To better understand racial/ethnic variability in rates, DCEG is conducting a genetic admixture study among African-American TGCT patients. As TGCT is much more prevalent in European-derived than in African-derived populations, the admixture approach can identify regions of unexpectedly high European-ancestry in African-American men with TGCT. These peaks of European chromosomal ancestry would identify underlying TGCT risk loci, because of underlying linkage disequilibrium between the ancestry informative SNP and any TGCT-causing genetic variant(s) with large differences in allele frequencies between the ancentral populations. To conduct this genetic admixture study, DCEG investigators are collaborating with a number of investigators at institutions across the U.S. Collaborators are contributing formalin-fixed, paraffin-embedded pathology blocks from which DNA is being obtained.
For more information, contact Katherine McGlynn.