Although testicular cancer is one of the most common cancers diagnosed in men ages 20 to 40—the average age at diagnosis is 33 and up to 10,000 men per year develop it—not much is known about the genetic scope of the disease and its early risk factors.

A new study led by a University of Pennsylvania consortium is potentially shedding light on the hereditary and genetic connections of the disease through the discovery of 22 new genetic locations within the testes that could signal a greater risk of testicular cancer onset. The number of loci known to be associated with this cancer is now at 78, a 40 percent increase from this single study. A locus is the physical location of a specific gene on a chromosome.

"Although we traditionally think that other cancer types can run in a family, testicular cancer is actually a higher [instance of that]," said