TP53 and breast cancer: Comparing our results with the overall frequency of TP53 p.R337H in southern Brazil, assumed by Custodio et al. (2013) to be in the range of 0.2–0.3% [16], we found that the TP53 p.R337H mutation frequency was significantly higher among breast cancer women with HBOC than in the general Brazilian population (p = 0.001 and 0.003 in comparison to 0.2 and 0.3%, respectively; one-sided exact binomial test).