title: BRCA1 and BRCA2 germline mutations in Malaysian women with early-onset breast cancer without a family history.
abstract: BACKGROUND
  In Asia, breast cancer is characterised by an early age of onset: In Malaysia, approximately 50% of cases occur in women under the age of 50 years. A proportion of these cases may be attributable, at least in part, to genetic components, but to date, the contribution of genetic components to breast cancer in many of Malaysia's ethnic groups has not been well-characterised.
  
  
  METHODS
  Given that hereditary breast carcinoma is primarily due to germline mutations in one of two breast cancer susceptibility genes, BRCA1 and BRCA2, we have characterised the spectrum of BRCA mutations in a cohort of 37 individuals with early-onset disease (<or=40 years) and no reported family history. Mutational analysis of BRCA1 and BRCA2 was conducted by full sequencing of all exons and intron-exon junctions.
  
  
  CONCLUSIONS
  Here, we report a total of 14 BRCA1 and 17 BRCA2 sequence alterations, of which eight are novel (3 BRCA1 and 5 BRCA2). One deleterious BRCA1 mutation and 2 deleterious BRCA2 mutations, all of which are novel mutations, were identified in 3 of 37 individuals. This represents a prevalence of 2.7% and 5.4% respectively, which is consistent with other studies in other Asian ethnic groups (4-9%).
authors.affiliation: Cancer Research Initiatives Foundation (CARIF), Outpatient Centre, Subang Jaya Medical Centre, Selangor, Malaysia.
authors.forename: Gaik Theng
authors.initials: GT
authors.lastname: Toh
authors.forename: Peter
authors.initials: P
authors.lastname: Kang
authors.forename: Sharlene S W
authors.initials: SS
authors.lastname: Lee
authors.forename: Daphne Shin-Chi
authors.initials: DS
authors.lastname: Lee
authors.forename: Sheau Yee
authors.initials: SY
authors.lastname: Lee
authors.forename: Suhaida
authors.initials: S
authors.lastname: Selamat
authors.forename: Nur Aishah
authors.initials: NA
authors.lastname: Mohd Taib
authors.forename: Sook-Yee
authors.initials: SY
authors.lastname: Yoon
authors.forename: Cheng Har
authors.initials: CH
authors.lastname: Yip
authors.forename: Soo-Hwang
authors.initials: SH
authors.lastname: Teo
mesh_terms: D000328:Adult; D017668:Age of Onset; D019313:BRCA1 Protein / Q000235:genetics*; D024682:BRCA2 Protein / Q000235:genetics*; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000235:genetics*; D005190:Family; D005260:Female; D018095:Germ-Line Mutation; D006801:Humans; D008296:Malaysia / Q000453:epidemiology
chemical_list: D019313:BRCA1 Protein; D024682:BRCA2 Protein