Abstract Specific pathogenic mutations associated with breast cancer development can vary between ethnical groups. One example is BRCA1 c.5266dupC that was first described as a founder mutation in the Ashkenazi Jewish population, but was later also found in other populations. In Brazil, this mutation corresponds to 20% of pathogenic BRCA1 variants reported. Our objective was to investigate the haplotype component of a group of Brazilian families who inherited c.5266dupC in the BRCA1 gene and to verify the ancestry contribution from European, African, and Amerindian origins. Fourteen probands carrying c.5266dupC and 16 relatives (carriers and non-carriers) were investigated. The same haplotype was observed segregating within all the families analyzed, revealing no recombinants in a region of 0.68 Mb. Ancestry analysis demonstrated that the European component was predominant among probands. The BRCA1 c.5266dupC analysis indicates that there was a founder effect in the Brazilian population.

Abstract Brazil is a country of continental dimensions and most genetic services are concentrated in the Southeast and South, including the Medical Genetics Service of the Hospital de Clínicas de Porto Alegre (MGS/HCPA). As many areas on the country do not have adequate medical genetics support, networks were designed to extend the service of the MGS/HCPA reference center. This paper presents the information and diagnosis networks that have their headquarters at MGS/HCPA: SIAT (National Information System on Teratogenic Agents), SIEM (Information Service on Inborn Errors of Metabolism), Alô Genética (Hello Genetics - Medical Genetics Information Service for Primary Health Care Professionals); Rede MPS Brasil (MPS-Mucopolysaccharidosis Brazil Network); Rede EIM Brasil (IEM-Inborn Errors of Metabolism Brazil Network), Rede NPC Brasil (Niemann-Pick C - NPC Brazil Network), Rede DLD Brasil (LSD-Lysosomal Storage Disorders Brazil Network), Rede DXB (MSUD-Maple Syrup Urine Disease Network), RedeBRIM (Brazilian Network of Reference and Information in Microdeletion Syndromes Project), Rede Neurogenética (Neurogenetics Network), and Rede Brasileira de Câncer Hereditário (Brazilian Hereditary Cancer Network). These tools are very useful to provide access to a qualified information and/or diagnostic service for specialized and non-specialized health services, bypassing difficulties that preclude patients to access reference centers.

Polimorfismos genéticos em genes relacionados com o metabolismo de xenobióticos, como os genes da superfamília das glutationa S-transferases (GSTM1, GSTT1 e GSTP1) têm sido associados com o aumento do risco para câncer de mama (CM). Considerando a alta incidência de CM na cidade de Porto Alegre, região Sul do Brasil, a proposta deste estudo foi caracterizar genótipos e frequências alélicas dos polimorfismos GSTM1, GSTT1 e GSTP1, e correlacionar esses achados moleculares com fatores de risco já estabelecidos para câncer de mama, incluindo densidade mamográfica, em uma amostra de 750 mulheres assintomáticas durante o rastreamento mamográfico. Para os testes moleculares foi utilizado multiplex da reação em cadeia de polimerase (PCR) para GSTM1 e GSTT1, e PCR quantitativo para o polimorfismo GSTP1. As frequências dos genótipos GSTM1 e GSTT1 nulos foram 45% e 21%, respectivamente. Para o polimorfismo GSTP1, as frequências genotipicas foram: 44% para o genótipo Ile/Ile, 44% para o genótipo Ile/Val e 12% para o genótipo Val/Val. A frequência do alelo lle nesta população foi 66%, semelhante a outros estudos. Houve uma associação significativa entre a combinação dos genótipos (T-/M-) nulos e densidade mamográfica nas mulheres pós-menopáusicas (p = 0,031). Quando analisamos isoladamente o genótipo GSTT1 nulo (T-) também encontramos uma associação significativa com a densidade mamográfica nas mulheres pós-menopáusicas (p = 0,027) e na amostra total. Estes achados sugerem uma associação dos genótipos (T-/M-) nulos com densidade mamográfica.

Genetic polymorphisms in genes related to the metabolism of xenobiotics, such as genes of the glutathione S-transferases (GSTM1, GSTT1, and GSTP1) superfamily have been associated with an increased risk for breast cancer (BC). Considering the high incidence of BC in the city of Porto Alegre in southern Brazil, the purpose of this study was to characterize genotypic and allelic frequencies of polymorphisms in GSTM1, GSTT1, and GSTP1, and correlate these molecular findings with established risk factors for breast cancer including mammographic density, in a sample of 750 asymptomatic women undergoing mammographic screening. Molecular tests were performed using the multiplex polymerase chain reaction (PCR) for GSTM1 and GSTT1, and quantitative PCR for GSTP1 polymorphisms. Overall, the frequencies of GSTM1 and GSTT1 null genotypes were 45% and 21%, respectively. For GSTP1 polymorphism, genotypic frequencies were 44% for the Ile/Ile genotype, 44% for the Ile/Val genotype, and 12% for Val/Val genotype, with an allelic frequency of 66% for the wild type allele in this population, similar to results of previous international publications. There was a statistically significant association between the combined GSTM1 and GSTT1 null genotypes (M-/T-) and mammographic density in post menopausal women (p = 0.031). When the GSTT1 null (T-) genotype was analyzed isolated, the association with mammographic density in post menopausal women and in the overall sample was also statistically significant (p = 0.023 and p = 0.027, respectively). These findings suggest an association of GSTM1 and GSTT1 null genotypes with mammographic density.

Polimorfismos genéticos em genes relacionados com o metabolismo de xenobióticos, como os genes da superfamília das glutationa S-transferases (GSTM1, GSTT1 e GSTP1) têm sido associados com o aumento do risco para câncer de mama (CM). Considerando a alta incidência de CM na cidade de Porto Alegre, região Sul do Brasil, a proposta deste estudo foi caracterizar genótipos e frequências alélicas dos polimorfismos GSTM1, GSTT1 e GSTP1, e correlacionar esses achados moleculares com fatores de risco já estabelecidos para câncer de mama, incluindo densidade mamográfica, em uma amostra de 750 mulheres assintomáticas durante o rastreamento mamográfico. Para os testes moleculares foi utilizado multiplex da reação em cadeia de polimerase (PCR) para GSTM1 e GSTT1, e PCR quantitativo para o polimorfismo GSTP1. As frequências dos genótipos GSTM1 e GSTT1 nulos foram 45% e 21%, respectivamente. Para o polimorfismo GSTP1, as frequências genotipicas foram: 44% para o genótipo Ile/Ile, 44% para o genótipo Ile/Val e 12% para o genótipo Val/Val. A frequência do alelo lle nesta população foi 66%, semelhante a outros estudos. Houve uma associação significativa entre a combinação dos genótipos (T-/M-) nulos e densidade mamográfica nas mulheres pós-menopáusicas (p = 0,031). Quando analisamos isoladamente o genótipo GSTT1 nulo (T-) também encontramos uma associação significativa com a densidade mamográfica nas mulheres pós-menopáusicas (p = 0,027) e na amostra total. Estes achados sugerem uma associação dos genótipos (T-/M-) nulos com densidade mamográfica.

Genetic polymorphisms in genes related to the metabolism of xenobiotics, such as genes of the glutathione S-transferases (GSTM1, GSTT1, and GSTP1) superfamily have been associated with an increased risk for breast cancer (BC). Considering the high incidence of BC in the city of Porto Alegre in southern Brazil, the purpose of this study was to characterize genotypic and allelic frequencies of polymorphisms in GSTM1, GSTT1, and GSTP1, and correlate these molecular findings with established risk factors for breast cancer including mammographic density, in a sample of 750 asymptomatic women undergoing mammographic screening. Molecular tests were performed using the multiplex polymerase chain reaction (PCR) for GSTM1 and GSTT1, and quantitative PCR for GSTP1 polymorphisms. Overall, the frequencies of GSTM1 and GSTT1 null genotypes were 45% and 21%, respectively. For GSTP1 polymorphism, genotypic frequencies were 44% for the Ile/Ile genotype, 44% for the Ile/Val genotype, and 12% for Val/Val genotype, with an allelic frequency of 66% for the wild type allele in this population, similar to results of previous international publications. There was a statistically significant association between the combined GSTM1 and GSTT1 null genotypes (M-/T-) and mammographic density in post menopausal women (p = 0.031). When the GSTT1 null (T-) genotype was analyzed isolated, the association with mammographic density in post menopausal women and in the overall sample was also statistically significant (p = 0.023 and p = 0.027, respectively). These findings suggest an association of GSTM1 and GSTT1 null genotypes with mammographic density.

FUNDAMENTOS: Aproximadamente 10% dos casos de melanoma são atribuíveis a mutações em genes de predisposição, sendo, portanto, hereditários. OBJETIVOS: Este estudo avalia a prevalência de fatores de risco para melanoma hereditário em um grupo de pacientes com melanoma no sul do Brasil. CASUÍSTICA E MÉTODOS: Foram estudados 195 pacientes com diagnóstico de melanoma admitidos consecutivamente no Hospital de Clínicas de Porto Alegre entre janeiro de 1999 e junho de 2000. RESULTADOS: A idade média ao diagnóstico de melanoma foi de 48 anos em homens e 44,9 anos em mulheres. Dos 133 pacientes cuja história familiar encontrava-se registrada no prontuário, 13 (9,8%) apresentavam história familiar de melanoma. A presença de ao menos um fator de risco importante para predisposição hereditária ao melanoma foi constatada em 31 pacientes (16%; IC 95% 10,9% - 21,1%). CONCLUSÃO: A possibilidade de influência do fator hereditário no Brasil estimula a procura ativa de fatores de risco genético em pacientes com melanoma, já que a identificação de famílias de alto risco pode ter grande impacto sobre a morbimortalidade de seus integrantes.

BACKGROUND: Approximately 10% of melanoma cases are attributable to cell line mutations in predisposition genes, and are therefore hereditary. OBJECTIVES: The present study evaluates the prevalence of hereditary melanoma risk factors in a group of patients diagnosed with the disorder in Southern Brazil. PATIENTS AND METHODS: One-hundred and ninety-five patients diagnosed with melanoma who were consecutively admitted to the Hospital de Clinicas de Porto Alegre between January 1999 and June 2000 were studied. RESULTS: The mean age at diagnosis of melanoma was 48 years in men and 45 years in women. From the 133 patients who had their family history registered in the hospital records, 13 (9.8%) had a family history of melanoma. The presence of at least one important risk factor for hereditary melanoma was observed in 31 patients (16%; CI 95%; 10.9-21.1%). CONCLUSIONS: The possibility of a genetic influence in melanoma cases of this region should stimulate the active search for specific hereditary melanoma risk factors, since the identification of at-risk patients may have an impact on disease morbidity and mortality.