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Medline ® Abstract for Reference 83

of 'Ataxia-telangiectasia'

Increased frequency of ATM mutations in breast carcinoma patients with early onset disease and positive family history.
Teraoka SN, Malone KE, Doody DR, Suter NM, Ostrander EA, Daling JR, Concannon P
Cancer. 2001;92(3):479.
BACKGROUND: An increased incidence of breast carcinoma has been reported among relatives of individuals who are affected with the rare recessive disorder, ataxia-telangiectasia (A-T), and who are heterozygous for mutations in the ataxia-telangiectasia mutated (ATM) gene. However, most studies of breast carcinoma cases from the general population have failed to find a higher incidence of ATM mutations in cases when compared with controls.
METHODS: Genomic DNA samples from 258 individuals were screened for mutations of all types in each of the 62 coding exons of the ATM gene; 142 of these were from breast carcinoma cases with a first-degree family history or early age at diagnosis, 35 were from cases selected for the presence of either known disease-related mutations (n = 25) or missense alterations of unknown consequences (n = 10) in BRCA1 or BRCA2, and 81 were from matched controls.
RESULTS: A total of 12 individuals with ATM mutations were identified, 11 among 142 breast carcinoma cases (7.7%; 95% CI, 3.9-13.4%) and 1 among 81 controls (1.2%; 95% CI, 0.0-6.7%) (P = 0.06). All mutations detected were of the missense type; none were predicted to truncate the ATM protein. Among cases, mutations were found exclusively in patients with a family history of breast carcinoma (12.1%; 95% CI, 6.2-20.6%) (P = 0.02). Similar frequencies of ATM mutations were found in 35 additional cases selected for the presence of BRCA1 or BRCA2 mutations when compared with cases overall.
CONCLUSIONS: ATM mutations, specifically missense mutations, are more common in breast carcinoma cases selected for first-degree family history and early age at diagnosis.
Molecular Genetics Program, Virginia Mason Research Center, 1201 Ninth Avenue, Seattle, WA 98101-2795, USA.