We provide an updated meta-analysis of rare variants identified by exome sequences and breast cancer risk in up to 74,127 cases and 748,181 controls, combining results from 12,695 cases from the Million Women Study with published summary statistics. Protein-truncating variants in established susceptibility genes BRCA2, BRCA1, CHEK2, PALB2, ATM and MAP3K1 were associated with a risk of breast cancer, while BARD1 and ATRIP met exome-wide significance for the first time.