title: Prevalence of BRCA1 and BRCA2 mutations in breast cancer patients from Brazil.
abstract: The contribution of BRCA1 and BRCA2 to breast cancer incidence in Brazil has not yet been explored. In order to estimate the proportion of breast cancers due to BRCA1 and BRCA2 mutations in Brazil, we conducted a study of unselected breast cancer patients from Rio de Janeiro, Brazil. We enrolled 402 women with breast cancer from a large public hospital and two private medical clinics in the city. A detailed family history was obtained from each patient and a blood sample was obtained for DNA analysis. Mutations in BRCA1 and BRCA2 were sought using a combination of techniques, but all mutations were confirmed by direct sequencing. Overall, nine mutations were identified (six in BRCA1 and three in BRCA2) representing 2.3% of the total. The most common mutation, 5382insC in BRCA1, was seen five times and accounted for 56% of all identified mutations. A second mutation, in BRCA2 (6633del5) was seen in two unrelated women. In summary, BRCA1 and BRCA2 mutations are not uncommon in Brazilian women with breast cancer. It appears that a small number of founder mutations may be predominant. Moreover, a small number of founder mutations may be prevalent in Brazil, raising the possibility that a rapid and inexpensive genetic test may be developed to screen for inherited susceptibility to breast cancer in Brazil.
authors.affiliation: Department of Oncology, Clementino Fraga Filho University Hospital, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Magda C B
authors.initials: MC
authors.lastname: Gomes
authors.forename: Mauricio M
authors.initials: MM
authors.lastname: Costa
authors.forename: Radovan
authors.initials: R
authors.lastname: Borojevic
authors.forename: Alvaro N A
authors.initials: AN
authors.lastname: Monteiro
authors.forename: Roberto
authors.initials: R
authors.lastname: Vieira
authors.forename: Sergio
authors.initials: S
authors.lastname: Koifman
authors.forename: Rosalina Jorge
authors.initials: RJ
authors.lastname: Koifman
authors.forename: Song
authors.initials: S
authors.lastname: Li
authors.forename: Robert
authors.initials: R
authors.lastname: Royer
authors.forename: Shiyu
authors.initials: S
authors.lastname: Zhang
authors.forename: Steven A
authors.initials: SA
authors.lastname: Narod
mesh_terms: D000328:Adult; D000368:Aged; D001938:Brazil; D001943:Breast Neoplasms / Q000235:genetics*; D004252:DNA Mutational Analysis; D005260:Female; D018703:Founder Effect; D019398:Genes, BRCA1; D024522:Genes, BRCA2; D005820:Genetic Testing; D006801:Humans; D008875:Middle Aged; D009154:Mutation; D015995:Prevalence