title: Incidence of BRCA1 and BRCA2 mutations in young Korean breast cancer patients.
abstract: OBJECTIVE
  The prevalence of BRCA-associated breast carcinoma in the Korean population has not been evaluated extensively.
  
  
  METHODS
  Sixty Korean women who developed breast cancer by age 40 years were studied. Lymphocyte specimens from peripheral blood were processed for BRCA1 and BRCA2 by complete sequencing. Family history through three generations was obtained. Available paraffin-embedded tissue blocks were processed for immunohistochemical staining.
  
  
  RESULTS
  In the cohort of 60 patients, nine patients with 11 deleterious mutations (six in BRCA1 and five in BRCA2) and seven missense mutations of unknown significance were found. Two patients had deleterious mutations in both BRCA1 and BRCA2 (double mutant). One half of the mutations were novel, and no founder mutations were observed in this cohort. Most of the BRCA-associated patients had no family history of breast and/or ovarian cancer. The expression of HER-2/neu, cyclin D1, and hormone receptors was less common, and p53 overexpression was more common in BRCA-associated tumors.
  
  
  CONCLUSIONS
  The prevalence of BRCA1 and BRCA2 mutations in Korean women with breast cancer at a young age was high. However, the penetrance, as evidenced by the low frequency of breast and ovarian cancers in family members, appears to be low. These data suggest that there may be different genetic and etiologic factors affecting transmission and penetrance of the BRCA genes in Korean patients with breast cancer diagnosed at a young age.
authors.affiliation: Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT 06520, USA.
authors.forename: Doo Ho
authors.initials: DH
authors.lastname: Choi
authors.forename: Min Hyuk
authors.initials: MH
authors.lastname: Lee
authors.forename: Allen E
authors.initials: AE
authors.lastname: Bale
authors.forename: Darryl
authors.initials: D
authors.lastname: Carter
authors.forename: Bruce G
authors.initials: BG
authors.lastname: Haffty
mesh_terms: D000328:Adult; D017668:Age of Onset; D001943:Breast Neoplasms / Q000208:ethnology* / Q000235:genetics*; D002277:Carcinoma / Q000208:ethnology* / Q000235:genetics*; D003430:Cross-Sectional Studies; D004252:DNA Mutational Analysis; D004273:DNA, Neoplasm / Q000032:analysis*; D005260:Female; D019398:Genes, BRCA1; D024522:Genes, BRCA2; D006801:Humans; D007150:Immunohistochemistry; D007723:Korea; D020125:Mutation, Missense; D010375:Pedigree; D016133:Polymerase Chain Reaction
chemical_list: D004273:DNA, Neoplasm