RAD51D and hypoparathyroidism-retardation-dysmorphism syndrome: HRD has been linked with genetic or epigenetic impairment of genes belonging to the BRCA-pathway such as BRCA1, BRCA2, PALB2 and RAD51B, RAD51C and RAD51D, but BRCA1 is the most frequently affected gene in TNBC (5, 6).