Analysis of BRCA1 and BRCA2 mutations in Brazilian breast cancer patients with positive family history.
OBJECTIVE
BRCA1 and BRCA2 are the two principal hereditary breast cancer susceptibility genes, and the prevalence of their mutations among Brazilian women is unknown. The objective was to detect BRCA1 and BRCA2 mutations in Brazilian patients with breast cancer, so as to establish genetic profiles.


METHODS
Cross-sectional study, in Centro de Atenção Integral à Saúde da Mulher, Universidade Estadual de Campinas, Brazil, and Institute of Pathology and Molecular Immunology, University of Porto, Portugal.


METHODS
Thirty-one breast cancer patients with positive family history (criteria from the Breast Cancer Linkage Consortium) were studied, and genomic DNA was extracted from peripheral blood. Single-strand conformation polymorphism was used for the analysis of exons 2, 3, 5, and 20 of BRCA1. Cases showing PCR products with abnormal bands were sequenced. Exon 11 of BRCA1 and exons 10 and 11 of BRCA2 were directly sequenced in both directions.


RESULTS
Four mutations were detected: one in BRCA1 and three in BRCA2. The BRCA1 mutation is a frameshift located at codon 1756 of exon 20: 5382 ins C. Two BRCA2 mutations were nonsense mutations located at exon 11: S2219X and the other was an unclassified variant located at exon 11: C1 290Y.


CONCLUSIONS
The BRCA1 or BRCA2 mutation prevalence found among women with breast cancer and such family history was 13% (4/31). Larger studies are needed to establish the significance of BRCA mutations among Brazilian women and the prevalence of specific mutations.
Dufloth
Rozany Mucha
RM
Centro de Atenção Integral à Saúde da Mulher, Faculdade de Ciências Médicas da Universidade Estadual de Campinas, Campinas, Sao Paulo, Brazil.
Carvalho
Sílvia
S
Heinrich
Juliana Karina
JK
Shinzato
Júlia Yoriko
JY
dos Santos
César Cabello
CC
Zeferino
Luiz Carlos
LC
Schmitt
Fernando
F
D000328:Adult; D001938:Brazil; D001943:Breast Neoplasms / Q000235:genetics*; D003430:Cross-Sectional Studies; D004252:DNA Mutational Analysis; D005260:Female; D019398:Genes, BRCA1; D024522:Genes, BRCA2; D020022:Genetic Predisposition to Disease; D005820:Genetic Testing; D006801:Humans; D009154:Mutation / Q000235:genetics*; D016133:Polymerase Chain Reaction; D018807:Polymorphism, Single-Stranded Conformational; D015995:Prevalence