The CHEK2 mutation c.593-1G>T, predicted to affect the splice site by three of the four queried in silico predictors (S1 Table) and reported as “likely pathogenic” in ClinVar, was found in a patient (HPC395) with a family history of three breast cancer (BrCa) cases, two of them diagnosed at early age (Fig 1B), thus fulfilling the B3 criterion. Here, CHEK2 is linked to breast cancer.