A total of 38 patients were positive for a pathogenic mutation, representing 15% of our Mexican women cohort with breast cancer: 25 for BRCA1 and 13 for BRCA2. Mutation distribution was uneven among molecular subtypes: 20% of the triple negative (TNBC) samples harbored pathogenic mutations in BRCA1 compared to 6.6% and 8% of the HR+ and Her2−, and Her2+ samples, respectively. The gene discussed is ERBB2; the disease is breast cancer.