Genome-wide association studies have reported more than 100 independent common loci associated with breast cancer risk. The contribution of low-frequency or rare variants to breast cancer susceptibility has not been well explored. Thus, we applied exome chip to genotype >200 000 low-frequency and rare variants in 1064 breast cancer cases and 1125 cancer-free controls and subsequently validated promising associations in another 1040 breast cancer cases and 1240 controls. We identified two low-frequency nonsynonymous variants at FKBPL (rs200847762, OR = 0.34, 95% CI = 0.20-0.57, P = 4.31 × 10-5 ) and ARPC1B (rs1045012, OR = 0.56, 95% CI = 0.43-0.74, P = 4.30 × 10-5 ) associated with breast cancer risk. In stratification analyses, we found that the protective effect of rs200847762 was stronger in ER-positive breast cancer (OR = 0.18, 95% CI = 0.06-0.42) than that in ER-negative one (OR = 0.59, 95% CI = 0.31-1.05). Our findings indicate that low-frequency variants may also contribute to breast cancer susceptibility and genetic variants in 6p21.33 and 7q22.1 are important in breast carcinogenesis. © 2016 Wiley Periodicals, Inc.
Keywords: ARPC1B; FKBPL; breast cancer; low-frequency variants; susceptibility.
© 2016 Wiley Periodicals, Inc.