%0 Journal Article %T Common variants in the ATM, BRCA1, BRCA2, CHEK2 and TP53 cancer susceptibility genes are unlikely to increase breast cancer risk %A Caroline Baynes %A Catherine S Healey %A Karen A Pooley %A Serena Scollen %A Robert N Luben %A Deborah J Thompson %A Paul DP Pharoah %A Douglas F Easton %A Bruce AJ Ponder %A Alison M Dunning %A the SEARCH breast cancer study %J Breast Cancer Research %D 2007 %I BioMed Central %R 10.1186/bcr1669 %X We have attempted a comprehensive, single nucleotide polymorphism (SNP)- and haplotype-tagging association study on each of these five genes in up to 4,474 breast cancer cases from the British, East Anglian SEARCH study and 4,560 controls from the EPIC-Norfolk study, using a two-stage study design. Nine tag SNPs were genotyped in ATM, together with five in BRCA1, sixteen in BRCA2, ten in CHEK2 and five in TP53, with the aim of tagging all other known, common variants. SNPs generating the common amino acid substitutions were specifically forced into the tagging set for each gene.No significant breast cancer associations were detected with any individual or combination of tag SNPs.It is unlikely that there are any other common variants in these genes conferring measurably increased risks of breast cancer in our study population.Four of the genes which lie in the DNA damage-recognition and repair pathway, ATM, BRCA1, BRCA2 and TP53, have mutations that are recognised to increase breast cancer susceptibility with moderate to high penetrance. Such mutations are very rare, and most probably of recent origin. A fifth gene, CHEK2, in the same pathway, has a deletion (1100delC) that reaches polymorphic frequencies (>0.01) in some European countries and doubles the risk of breast cancer in female carriers [1]. Together these mutations account for only a small proportion (2% to 5%) of all breast cancer incidences [2,3]. Breast cancer is, however, a common disease and genetic epidemiological data suggest that there is a low-penetrance genetic contribution to most cases [4,5]. It is likely that at least a part of breast cancer aetiology will fit the common disease-common variant hypothesis, which states that patients with a common, complex disease are likely to share some common, low-penetrance alleles that increase their susceptibility to that disease. This raises the question of whether such common, polymorphic susceptibility alleles exist within these five genes in addition t %U http://breast-cancer-research.com/content/9/2/R27