ABSTRACT
The reports provided by OMS in 2011 have showed that cancer is a major cause of death in the world, causing 7.6 million deaths in 2008. Breast cancer is in the world, the most common neoplasia of women, and it appears that low penetrance genes, but frequently mutated in the general population play an important role in the development of this cancer. The objective of this study is to evaluate the involvement of Cytochrome b mutations (mitochondrial gene) in the occurrence of breast cancer in the Senegalese women. We have analyzed by PCR-sequencing the variability of the Cytochrome b gene in thirty Senegalese patients suffering from breast cancer. The results of molecular analysis of a portion of Cytochrome B indicate the existence of nucleotide variability at intra and interindividual with a genetic differentiation between healthy and cancerous tissue, as well as the existence of a correlation between this genetic differentiation at the age of the patients and location of tumors (right breast or left breast). Changes of one or more Tryptophan to other amino acids, ranging normal tissue to cancerous tissue, are noted in some individuals with a penetrance of 72.41%. Our results also show a significant increase (79.3%) the number of Phenylalanine in cancerous tissues with very different proportions between individuals. Any increase in the rate of Tryptophan and Phenylalanine in cancerous tissues could be correlated with an increased risk of developing breast cancer.