Our diagnostic yield of TP53 testing in early-onset breast cancer patients is comparable with a study conducted by Bakhuizen et al. in a large national cohort of 370 women diagnosed with breast cancer before the age of 31 [25] and the result of a British multicenter study with an overall detection rate of the TP53 PV/LPV germline variant of 3.3% in all women diagnosed with breast cancer at <30 years of age [26]. Here, TP53 is linked to breast cancer.