BRCA1 and breast cancer: RAD50, MRE11 and NBS1 gene sequencing in eight patients from non-BRCA1/2 breast cancer families whose tumours also showed low/loss of RAD50, MRE11 and NBS1 revealed two germline mutations in MRE11, specifically, a missense mutation R202G and a truncating mutation R633STOP (R633X)23.