To address this question, we sequenced all exons and exon-intron boundaries in 56 genes that are plausibly associated with breast cancer risk SNPs in index cases from 1043 familial breast cancer families who previously had negative test results for BRCA1 or BRCA2 pathogenic mutations and 944 population-matched cancer-free control participants from an Australian population. This evidence concerns the gene BRCA1 and breast cancer.