Nature Genetics
Published online: 29 March 2009
Newly discovered breast cancer susceptibility loci on 3p24 and 17q23.2Genome-wide association studies (GWAS) have identified seven breast cancer susceptibility loci, but these explain only a small fraction of the familial risk of the disease. Five of these loci were identified through a two-stage GWAS involving 390 familial cases and 364 controls in the first stage, and 3,990 cases and 3,916 controls in the second stage1. To identify additional loci, we tested over 800 promising associations from this GWAS in a further two stages involving 37,012 cases and 40,069 controls from 33 studies in the CGEMS collaboration and Breast Cancer Association Consortium. We found strong evidence for additional susceptibility loci on
3p (rs4973768: per-allele OR = 1.11, 95% CI = 1.08–1.13, P = 4.1 times 10-23) and
17q (rs6504950: per-allele OR = 0.95, 95% CI = 0.92–0.97, P = 1.4 times 10-8). Potential causative genes include SLC4A7 and NEK10 on 3p and COX11 on 17q.
Nature Genetics
Published online: 29 March 2009
A multistage genome-wide association study in breast cancer identifies two new risk alleles at 1p11.2 and 14q24.1 (RAD51L1)We conducted a three-stage genome-wide association study (GWAS) of breast cancer in 9,770 cases and 10,799 controls in the Cancer Genetic Markers of Susceptibility (CGEMS) initiative. In stage 1, we genotyped 528,173 SNPs in 1,145 cases of invasive breast cancer and 1,142 controls. In stage 2, we analyzed 24,909 top SNPs in 4,547 cases and 4,434 controls. In stage 3, we investigated 21 loci in 4,078 cases and 5,223 controls. Two new loci achieved genome-wide significance. A pericentromeric SNP on chromosome
1p11.2 (rs11249433; P = 6.74 times 10-10 adjusted genotype test, 2 degrees of freedom) resides in a large linkage disequilibrium block neighboring NOTCH2 and FCGR1B; this signal was stronger for estrogen-receptor–positive tumors. A second SNP on chromosome
14q24.1 (rs999737; P = 1.74 times 10-7) localizes to RAD51L1, a gene in the homologous recombination DNA repair pathway. We also confirmed associations with loci on chromosomes 2q35, 5p12, 5q11.2, 8q24, 10q26 and 16q12.1.