ATM and breast cancer: These findings are consistent with two earlier studies: one study of the British families that first identified the 7271T>G mutation and reported a similarly large increased risk of breast cancer among three carriers of that mutation (RR=12.7, 95% CI 3.7–45.8) (Stankovic et al, 1998); and a second study by Broeks (Broeks et al, 2000) of early-onset female breast cancer, where three out of the seven ATM mutations found were IVS10-6T>G.