TP53 and cancer: Carrier frequency in the second group of patients (diagnosed at or below 45 years who were recruited from a cancer genetics clinic and did not have criteria for TP53 mutation testing) was 2.5% similar to mutation prevalences observed in 2 previous studies that included women with a FH compatible with hereditary breast and ovarian cancer syndrome, 0.94% and 2.5% [19, 20].