Genetic variants associated with susceptibility to testicular germ cell cancer are reported this week in Nature Genetics. Testicular germ cell cancer (TGCT) is the most common cancer in men aged 15-45.
Clare Turnbull and colleagues conducted a genome-wide association study for TGCT in 979 cases, with replication in an additional 664 cases. They identify three genomic regions newly associated with susceptibility to TGCT. This includes two candidate genes, TERT and ATF7IP, involved in telomere regulation. Unusually shortened telomeres, the regions of repetitive DNA at the ends of a chromosome, have been found in many cancer types. Telomerase, which regulates telomere length, is highly expressed in testicular germ cells as well as a high proportion of cancer cells. TERT, coding for component of telomerase, has also been associated with several other cancer types. The third associated genetic region includes the sex determination gene DMRT1, which has also been implicated in testicular determination and differentiation.