Disruption of the ATM gene in breast cancer

Mutations in the A TM gene, which maps to 11q22-23, cause the multisystem r ecessive syndrome ataxia-telangiectasia (AT). Breast cancer has been report ed in AT patients and carriers. Sporadic breast cancer is associated with l oss of heterozygosity at or in the region of ATM and chromosomal abnormalit ies involving 11q23. We have investigated the chromosomes, nuclei and relea sed chromatin fibers from nine primary breast carcinoma and eight cell line s by fluorescence in situ hybridization with four fluorochrome-labeled cosm ids spanning the ATM gene. The ATM gene was disrupted in one primary breast carcinoma and in the cell lines MDA-MB-231 and MCF-7. The role of these ab errations in breast carcinomas, which may lead to gene dosage or dominant n egative effects on gene function, requires further investigation. (C) 2001 Elsevier Science Inc. Ah rights reserved.