Should women be allowed access to a genetic test for breast cancer risk?Last week, the Icelandic company deCODE Genetics began offering a new breast cancer gene test that it claims measures genetic risk for the common forms of the disease. The new test assesses seven single-letter variations (a.k.a., single nucleotide polymorphisms) in the human genome that researchers have linked to higher risk of breast cancer. The average lifetime risk for women of European descent is 12 percent. The company claims that its new test can tell a woman if her lifetime risk of breast cancer is as low as 5...