http://breast-cancer-research.com/content/9/S1/S13
"Basal-like breast cancer has some unique characteristics. It is the type of breast cancer that BRCA1 mutation carriers generally develop, although most basal-like breast cancers are sporadic. It comprises approximately 15% of all breast cancers, but is overrepresented among young African-American women who develop breast cancer, in whom it comprises 39%. "