The discovery of 12 new genetic risk variants for testicular cancer is reported in two studies published this week in Nature Genetics.

Testicular germ cell tumor is the most common cancer in young men, with peak incidence among those aged 25 to 34 years.

Katherine Nathanson and colleagues performed a meta-analysis of three genome-wide association studies of testicular germ cell tumor, with follow-up replication testing in six additional sample collections. They identified four new chromosomal regions associated with increased risk of this disease. In a separate study, Clare Turnbull and colleagues performed a meta-analysis of data from a genome-wide association study and a large replication study and identified nine new susceptibility variants for testicular cancer, one of which overlapped with one of the variants identified by Nathanson and colleagues. Several of the risk variants identified in these studies reside near genes important for male germ cell development.