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

AIM: 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. METHODS: 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. RESULTS: 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.insC) suggesting his implication in the modulation of the BRCA1 deleterious mutations penetrance.