TP53 and breast cancer: This is consistent with reports in other studies, where 0.8 to 5% frequency was reported among breast cancer patients diagnosed ≤ 40 years: in an clinic-based cohort of patients ≤ 40 years, 1/126 (0.8%) had a TP53 missense mutation [22]; in a Singaporean clinic-based cohort of breast cancer patients ≤ 35 years, 1/30 (3.3%) patients had a deleterious TP53 mutation [23]: in an Australian population-based cohort of two subgroups of early-onset breast cancer patients (≤ 30 years and 31 to 39 years), 5/94 (5.3%) had germline TP53 mutations [10].