BRCA1 and breast cancer: For self-reported BMI, when stratified by BRCA1/2 pathogenic germline gene variant, adulthood BMI was inversely associated with breast cancer risk for women with BRCA2 pathogenic germline gene variant, but not BRCA1 pathogenic germline gene variant, and young-adulthood BMI was inversely associated with risk among women with BRCA1 and BRCA2 pathogenic germline gene variants [29].