Molecular Genetic variability in the D-loop region for females with Breast Cancer and the effect of the Chemotherapy

Abstract

The mitochondrial DNA (mtDNA) is a small circular genome placed within the mitochondria in the cytoplasm of the cell, had a smaller 1.1 kbp fragment and called the Displacement loop (D-loop). This paper aims to find the degree of variation characteristics of this fragment. The majority of the Polymorphism nucleotidewerelocated in the D-loop region,the nucleotide transition,transversion, insertion and deletion were the importantvariations in nucleotide sequencingin females who had a breast cancer. The comparison was made between females suffering from breast cancer who didn't took chemotherapy and others treated with chemotherapy. The results were compared with a local sequence (Muthana-1) in NCBI; the total number of mutations was 36 mutations (32.1%) for patients who didn't take chemotherapy, while 76 mutations (67.8%) for the patients who were given chemotherapy. The most common and frequent mutations in D-loop in females with breast cancer were the transition then transversion mutation. The total number of transition was 14 mutations (38.8%) in females without chemotherapy. On the other hand, in females who were given chemotherapy, the total number of this mutation was 33 mutations (43.4%), which was more frequent than of those who did not take chemotherapy. The total number of transversion mutations was 9 mutations (25%) in females without chemotherapy, which was less frequent and repeated comparing to the transition mutations in the same samples. In females who took chemotherapy, there were 19 mutations (25%), which was more frequent and repeated than those who didn't took chemotherapy. The total number of deletion mutations in the D-loop region was 10 mutations (27.7%) in females who didn't took chemotherapy. In contrast to the females who took chemotherapy, there were 17 mutations (22.3%). In the insertion mutations, the total number of mutations was 3 (8.3%) in females who didn't took chemotherapy, while 7 mutations (9.2%) in females who took chemotherapy. The chemotherapy makes the mtDNA in general and D-loop in particular have a high sensitivity to damage and have variations