Prevalence of BRCA1/BRCA2 mutations in a Brazilian population sample at-risk for hereditary breast cancer and characterization of its genetic ancestry.

BACKGROUND: There are very few data about the mutational profile of families at-risk for hereditary breast and ovarian cancer (HBOC) from Latin America (LA) and especially from Brazil, the largest and most populated country in LA. RESULTS: Of the 349 probands analyzed, 21.5% were BRCA1/BRCA2 mutated, 65.3% at BRCA1 and 34.7% at BRCA2 gene. The mutation c.5266dupC (former 5382insC) was the most frequent alteration, representing 36.7% of the BRCA1 mutations and 24.0% of all mutations identified. Together with the BRCA1 c.3331_3334delCAAG mutation, these mutations constitutes about 35% of the identified mutations and more than 50% of the BRCA1 pathogenic mutations. Interestingly, six new mutations were identified. Additionally, 39 out of the 44 pathogenic mutations identified were not previously reported in the Brazilian population. Besides, 36 different variants of unknown significance (VUS) were identified. Regarding ancestry, average ancestry proportions were 70.6% European, 14.5% African, 8.0% Native American and 6.8% East Asian. MATERIALS AND METHODS: This study characterized 349 Brazilian families at-risk for HBOC regarding their germline BRCA1/BRCA2 status and genetic ancestry. CONCLUSIONS: This is the largest report of BRCA1/BRCA2 assessment in an at-risk HBOC Brazilian population. We identified 21.5% of patients harboring BRCA1/BRCA2 mutations and characterized the genetic ancestry of a sample group at-risk for hereditary breast cancer showing once again how admixed is the Brazilian population. No association was found between genetic ancestry and mutational status. The knowledge of the mutational profile in a population can contribute to the definition of more cost-effective strategies for the identification of HBOC families.

Listeriose humana: prevalência dos sorotipos de Listeria monocytogenes isolados no Brasil / Human listeriosis: incidence of serotypes of Listeria monocytogenes isolated in Brazil

Foram caracterizadas sorologicamente 71 amostras de Listeria monocytogenes, isoladas de processos patológicos e de portadores humanos, no período de 1969 a 1983. As amostras estudadas originaram-se de diferentes regiões do país, representadas pelos Estados de São Paulo, Rio de Janeiro, Pernambuco e Bahia. A análise sorológica permitiu o reconhecimento de sete sorotipos distintos, destacando-se 1:0 cômputo geral a predominãncia de L 4b (50,70%) sobre L 1/2a (29,57%). Em plano secundário, foram detectados os sorotipos L 4a (7,04%); L 4ab (5,e3%); L 1/2b (1,40%); L 1/2c (1,40%) e L 4g (1,40%) (AU).