title: The prevalence of BRCA1 mutations in Chinese patients with early onset breast cancer and affected relatives.
abstract: The purpose of this study was to determine the prevalence of BRCA1 mutations in Chinese breast cancer patients in Singapore. BRCA1 analysis was conducted in consecutive patients with breast cancer before the age of 40 years (76 women), or whose relatives had breast or ovarian cancer (16 women). Ten patients had both early onset breast cancer and affected relatives. Genomic DNA from peripheral mononuclear blood cells was studied by using the protein transcription-translation assay (exon 11) and single-strand conformational polymorphism, with subsequent DNA sequencing. All six disease-causing mutations occurred in women under 40 years (8.6%) with three occurring in patients under 35 years (three out of 22 patients, 13.6%). Mis-sense mutations of unknown significance were found in three patients. Two of the ten women with affected relatives under 40 years had BRCA1 mutations. The prevalence of BRCA1 mutations in Chinese patients with early onset breast cancer is similar to that observed in Caucasian women. Most Chinese patients with affected relatives were not carriers of BRCA1 mutations.
authors.affiliation: Oncology Research Institute (National University Medical Institutes) and Department of Medical Oncology, National University of Singapore, Singapore.
authors.forename: J H
authors.initials: JH
authors.lastname: Sng
authors.forename: J
authors.initials: J
authors.lastname: Chang
authors.forename: F
authors.initials: F
authors.lastname: Feroze
authors.forename: N
authors.initials: N
authors.lastname: Rahman
authors.forename: W
authors.initials: W
authors.lastname: Tan
authors.forename: S
authors.initials: S
authors.lastname: Lim
authors.forename: M
authors.initials: M
authors.lastname: Lehnert
authors.forename: S
authors.initials: S
authors.lastname: van der Pool
authors.forename: J
authors.initials: J
authors.lastname: Wong
mesh_terms: D000328:Adult; D019313:BRCA1 Protein / Q000235:genetics*; D001943:Breast Neoplasms / Q000208:ethnology / Q000235:genetics*; D002681:China / Q000208:ethnology; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008875:Middle Aged; D020125:Mutation, Missense; D020641:Polymorphism, Single Nucleotide
chemical_list: D019313:BRCA1 Protein