RESUMO
The present study was undertaken to examine the frequencies of GSTM1 (Null/Present), GSTP1 (Ile105Val) and p53 (Arg72Pro) genotypes and their relations to breast cancer susceptibility in South Indian women. This case - control study involved 250 consecutive breast cancer cases and 500 healthy controls matched in five-year age categories in the ratio of 1:2. Genotyping was performed by PCR for GSTM1, Real-Time Allelic discrimination assay for GSTP1 and PCR-CTPP for p53. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using conditional logistic regression after adjusting for the known risk factors for breast cancer. The frequencies for the GSTM1 Null genotype were 26% in the cases and 22% in the controls; for GSTP1 Ile/Ile, Ile/Val, Val/Val the frequencies were 46.6%, 41.9% and 11.5%, respectively, in cases and 46.0%, 43.8% and 10.2% in controls; for p53 Arg/Arg, Arg/Pro & Pro/Pro the frequencies were 26.4%, 50.0% and 23.6% in cases and 27.0%, 44.8% and 28.2% in controls. A nonsignificant elevation in breast cancer risk was observed among women who had the GSTM1 Null genotype (OR=1.24; 95% CI=0.83-1.84), the p53 Arg/Arg genotype (OR=1.28; 95% CI=0.81-2.03) and the Pro/Arg genotype (OR=1.49; 95% CI=0.99-2.25), and the GSTP1 Val/Val genotype (OR=1.1; 95% CI=0.64-1.91).
Assuntos
Substituição de Aminoácidos , Neoplasias da Mama/epidemiologia , DNA de Neoplasias/genética , Feminino , Genótipo , Glutationa S-Transferase pi/genética , Glutationa Transferase/deficiência , Humanos , Índia , Pessoa de Meia-Idade , Razão de Chances , Polimorfismo Genético , Polimorfismo de Nucleotídeo Único , Religião , Fatores de Risco , Proteína Supressora de Tumor p53/genéticaRESUMO
Cancer of the breast is the second most common cancer seen among Indian women. This study describes the use of DHPLC for mutation analysis for BRCA1, BRCA2 and CHEK2 (1100delC) in 22 patients with a family history of breast and/or ovarian cancer and early onset breast cancer (<35 years of age). Three of the 22 patients were found to have a non-sense mutation or a deletion, resulting in a premature stop codon, potentially leading to a truncated protein. Two of these were in BRCA1 (one was a novel 5 base deletion) and one in the BRCA2 gene. No patient was found in our series to have the CHEK2 (1100delC) mutation. DNA from a healthy blood donor and all but one of the 22 patients, demonstrated polymorphisms in BRCA1 and/or BRCA2 genes. This is the first study from South India, on BRCA1, BRCA2 & CHEK2 (1100 del C) mutations in patients with a family history of breast and/or ovarian cancer and early onset breast/ovarian cancer, using the sensitive DHPLC approach.