The KRAS variant allele was detected in 17.2% of sporadic breast cancer cases and in 18.2% of all familial cases (10.3% of BRCA carriers - 10.0% of BRCA1 and 11.1% of BRCA2 carriers and in 19.9% of non-BRCA carriers). The gene discussed is BRCA2; the disease is breast carcinoma.