Population-based estimates of breast cancer risks associated with ATM gene variants c.7271T > G and c.1066-6T > G (IVS10-6T > G) from the breast cancer family registry

Abstract

The ATM gene variants segregating in ataxia-telangiectasia families are associated with increased breast cancer risk, but the contribution of specific variants has been difficult to estimate. Previous small studies suggested two functional variants, c.7271T > G and c.1066-6T > G (IVS10-6T > G), are associated with increased risk. Using population-based blood samples we found that 7 out of 3,743 breast cancer cases (0.2%) and 0 out of 1,268 controls were heterozygous for the c.7271T > G allele (P = 0.1). In cases, this allele was more prevalent in women with an affected mother (odds ratio [OR] = 5.5, 95% confidence interval [CI] = 1.2-25.5; P = 0.04) and delayed child-bearing (OR = 5.1; 95% C..