TP53 and breast carcinoma: TP53 exon 1 encodes the 5′ untranslated-region (UTR) shown to be critical for RPL26-mediated translation of p53 mRNA upon DNA damage.24 Reported carriers of TP53 promoter or exon 1 deletion mostly presented soft tissue sarcomas and breast cancer.20,25–27 Somatic LOH reflected by homozygous deletion of this region in our patient’s tumour (Supplementary Figure 1) implicates deleterious effect of this variation.