BRCA1 and breast cancer: A family history of breast cancer is a significant risk factor, with 13 – 19% of breast cancer patients reporting a first-degree relative (mother, sister, or daughter) with the disease.35 Individuals with a first-degree relative diagnosed with breast cancer before the age of 40 face a 14.1% increased risk of developing the disease within the next 10 years.36 This risk is further elevated in women carrying predisposing mutations in the BRCA1 or BRCA2 genes.