Revisiting breast cancer patients who previously tested negative for BRCA mutations using a 12-gene panel (original) (raw)

BRCA mutations contribute to about 20% of all hereditary breast cancers. With full-genome sequencing as the emerging standard for genetic testing, other breast cancer susceptibility genes have been identified and may collectively contribute to up to 30% of all hereditary breast cancers. We re-assessed women who had previously tested negative for a BRCA mutation when outdated techniques were used, and discuss the implications of identifying a mutation several years after initial genetic testing. We evaluated the prevalence of mutations in 12 breast cancer susceptibility genes (including BRCA1 and BRCA2) in 190 breast cancer patients with a strong family history of breast cancer. These women had previously tested negative for mutations in the large coding exons of BRCA1 and BRCA2 using the protein truncation test (PTT) between the years of 1996 and 2013. We identified pathogenic mutations in 17 of 190 (9%) women. Six mutations were detected in BRCA1 (n = 2) and BRCA2 (n = 4). Eleven m...