Investigating how high-risk genetic mutations affect age at onset, Ford et al. [26] observed that 5.3 % of breast cancers in <40 year olds are attributable to BRCA1 mutations compared 2.2 % and 1.1 % in 40- to 49-year olds and 50- to 70-year olds, respectively. The gene discussed is BRCA1; the disease is breast carcinoma.