BRCA1 and cancer: With striking similarity to our findings, they reported that 11 of 18 (61.1%) with a family history of cancer carried BRCA1 or 2 mutations, while only 7 of 52 (13.5%) without any family history did.22, 23 A family‐based assessment of BRCA1 or 2 mutations conducted in 283 OC families in the United Kingdom and in the United States identified coding sequence changes and genomic rearrangements in 46% of the families.