ATM and breast cancer: Sixty-one percent of patients (28/46) had PVs in a high-penetrance gene for BC: 19 (8.5%) in BRCA1/2, 8 (3.5%) in TP53, and 1 (0.5%) in PALB2. Moderate penetrance genes for BC (ATM, CHEK2) represented 15.2% (7/46) of the positive results: 6 (13%) patients had PV in CHEK2 and 1 (2.1%) in ATM. PVs in genes considered to have a potential increased risk of BC (BARD1, RAD51C, RAD51D) or an unknown risk/insufficient data (MUTYH, MSH6, RECQL4) were found in 23.9% (11/46) of patients.