Mutation analysis of the ATR gene in breast and ovarian cancer families.

Introduction: Mutations in BRCA1, BRCA2, ATM, TP53, CHK2 and PTEN account for only 20-30% of the familial aggregation of breast cancer, which suggests the involvement of additional susceptibility genes. The ATR (ataxia-telangiectasia- and Rad3-related) kinase is essential for the maintenance of genomic integrity. It functions both in parallel and cooperatively with ATM, but whereas ATM is primarily activated by DNA double-strand breaks induced by ionizing radiation, ATR has been shown to respond to a much broader range of DNA damage.