DNA methylation profiling in breast cancer discordant identical twins

We obtained a comprehensive DNA methylation profile of 15 breast cancer discordant twins, using the high resolution Infinium HumanMethylation450 BeadChip platform (450K, Illumina), previously established to reliably detect methylation changes of more than 450,000 CpG sites. To provide insight into the temporal and causal relationships and predictive potential, samples from breast cancer patients before (7) and after diagnosis (8) were also analyzed. Using whole blood from 15 twin pairs discordant for breast cancer and high-resolution (450k) DNA methylation analysis we identified 403 differentially methylated CpG sites including known and novel potential breast cancer genes. 30 Samples