RESUMEN
PURPOSE: To understand the involvement of BRCA1 gene in Korean breast and/or ovarian cancer families. MATERIALS AND METHODS: Germline mutations of BRCA1 gene were analyzed in 13 families which included 3 hereditary site-specific breast cancer families, 6 suspected breast cancer families, and 3 suspected breast-ovarian cancer family, and one Li-Fraumeni family by screening BRCA1 gene using single strand conformation polymorphism (SSCP) analysis on polymerase chain reaction (PCR) amplified genomic DNA and confirmed the results by sequencing. RESULTS: Including one family with previously reported nonsense mutation of BRCA1 gene, we detected two mutations in unrelated families. One newly identified mutation was frame shift mutation resulting from TG deletion in codon 1701, which results in a truncated BRCA1 protein, at codon 1714. CONCLUSION: The proportion of families who inherit the mutated BRCA1 gene seems to be small among Korean breast and/or ovarian cancer families.