BRCA1 and breast cancer: For BRCA1 only, a mutation frequency of 0.4% is found in Finnish (Syrjakoski et al, 2000), 2.1% in Dutch (Papelard et al, 2000), 3% in Polish (Gorski et al, 2005), <1% in Swedish (Margolin et al, 2004), 1.5% in Brazilian (Gomes et al, 2007), and 2.4–3.5% in US unselected breast cancer patients (Newman et al, 1998; Malone et al, 2006; John et al, 2007).