These carrier frequencies are much higher than those reported from population-based screening of African American patients with breast cancer on the basis of earlier mutation detection methods19 and are more comparable to carrier frequencies among African American women referred for clinical genetic testing.20,21 Mutations in PALB2 and TP53 also confer a significantly elevated risk, although mutations in these genes were less frequent, and risks were not estimable because no mutations appeared in controls. Here, TP53 is linked to breast carcinoma.