Genetic variants associated with the density of the breast tissues are reported this week in Nature Genetics. Women with a high mammographic density, a measurement of the density of breast tissue, have shown increased risk for breast cancer.
Rulla Tamimi and colleagues report a meta-analysis of five genome-wide association studies for percent mammographic density, with a total sample size of 4,877 women, and replication in two additional cohorts including 2,835 women. They identify genetic variants in the gene ZNF365 associated with percent mammographic density adjusted for age and body mass index. Variants in this gene have also been associated with susceptibility to breast cancer.