[Penetrance of BRCA1 gene mutation and DNA mitochondrial in Tunisian breast cancer occurrence]

The aim of this study is to evaluate the implication of BRCA1 gene and the mitochondrial micro satellite [situated between 303 and 315 positions] mutations in the occurrence of breast cancer in Tunisia. Nine Tunisian patients with hereditary breast cancer have been analyzed. For each patient, total genomic DNA was extracted and used as a template for the amplification of 24 exons of the BRCA1 gene and an hyper variable mitochondrial region. The obtained products were purified and automatically sequenced. The results revealed five types of mutations for the micro satellite situated between the 303 and 315 positions and two deleterious BRCA1 mutations for two unrelated patients which present the same mitochondrial mutation [315. ins C] suggesting his implication in the modulation of the BRCAI deleterious mutations penetrance

Are JLA DQB1 alleles correlated with breast cancer histoprognostic parameteres in Tunisia?

Tumor cells express surface structures different from normal cells. These structures may be recognized by the immune system, which ensure anti-tumoral surveillance. Antigenic presentation requires HLA molecules role. Since, these molecules are encoded by a high polymorphic system, immune response can be modulated according to HLA genotype. So, HLA polymorphism could be correlated with tumor escape from anti-tumor immunosurveillance. We have aimed to search for possible associations between HLA DQB 1 alleles and the histoprognostical parameters in breast cancer in the Tunisian population. DQB 1 alleles were determined by PCR-SSO molecular typing in 100 healthy matched and unrelated Tunisian female and 87 Tunisian women with breast cancer. Allelic distribution between the two studied groups showed no significant associations between this locus and the occurrence, the EE grade and the lymph node invasion of breast cancer in the Tunisian population. This result may be explained by the fact that cancer is a multifactoral disease due to several interacting factors that might change from one population to another