Dominant negative ATM mutations in breast cancer families

J Natl Cancer Inst. 2002 Feb 6;94(3):205-15. doi: 10.1093/jnci/94.3.205.

Abstract

Background: The ATM gene encoding a putative protein kinase is mutated in ataxia-telangiectasia (A-T), an autosomal recessive disorder with a predisposition for cancer. Studies of A-T families suggest that female heterozygotes have an increased risk of breast cancer compared with noncarriers. However, neither linkage analyses nor mutation studies have provided supporting evidence for a role of ATM in breast cancer predisposition. Nevertheless, two recurrent ATM mutations, T7271G and IVS10-6T-->G, reportedly increase the risk of breast cancer. We examined these two ATM mutations in a population-based, case-control series of breast cancer families and multiple-case breast cancer families.

Methods: Five hundred twenty-five or 262 case patients with breast cancer and 381 or 68 control subjects, respectively, were genotyped for the T7271G and IVS10-6T-->G ATM mutations, as were index patients from 76 non-BRCA1/2 multiple-case breast cancer families. Linkage and penetrance were analyzed. ATM protein expression and kinase activity were analyzed in lymphoblastoid cell lines from mutation carriers. All statistical tests were two-sided.

Results: In case and control subjects unselected for family history of breast cancer, one case patient had the T7271G mutation, and none had the IVS10-6T-->G mutation. In three multiple-case families, one of these two mutations segregated with breast cancer. The estimated average penetrance of the mutations was 60% (95% confidence interval [CI] = 32% to 90%) to age 70 years, equivalent to a 15.7-fold (95% CI = 6.4-fold to 38.0-fold) increased relative risk compared with that of the general population. Expression and activity analyses of ATM in heterozygous cell lines indicated that both mutations are dominant negative.

Conclusion: At least two ATM mutations are associated with a sufficiently high risk of breast cancer to be found in multiple-case breast cancer families. Full mutation analysis of the ATM gene in such families could help clarify the role of ATM in breast cancer susceptibility.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Ataxia Telangiectasia Mutated Proteins
  • Blotting, Western
  • Breast Neoplasms / genetics*
  • Breast Neoplasms / pathology
  • Cell Cycle Proteins
  • Chromosome Mapping
  • DNA Mutational Analysis
  • DNA-Binding Proteins
  • Female
  • Gene Frequency / genetics
  • Genes, Dominant / genetics*
  • Genetic Predisposition to Disease / genetics
  • Genetic Testing*
  • Genotype
  • Humans
  • Lod Score
  • Male
  • Microsatellite Repeats / genetics
  • Mutation / genetics*
  • Pedigree
  • Protein-Serine-Threonine Kinases / genetics*
  • Protein-Serine-Threonine Kinases / metabolism
  • Tumor Cells, Cultured
  • Tumor Suppressor Proteins

Substances

  • Cell Cycle Proteins
  • DNA-Binding Proteins
  • Tumor Suppressor Proteins
  • ATM protein, human
  • Ataxia Telangiectasia Mutated Proteins
  • Protein-Serine-Threonine Kinases