The Impact of Sequencing Human Genome on Breast Cancer
Hameed Khan, Ph.D.
ABSTRACT
An estimated 42,140 women in the U.S. die from breast cancer this year. Approximately 321,910 new cases of invasive breast cancer are expected to be diagnosed next year. Worldwide 670,000 to 764,000 deaths occur annually making it the leading cause of cancer death among women. Current treatments include surgery and chemotherapy. After surgery, the most widely used compounds for treating breast cancer are Taxanes and Anthracyclines. After the
surgery and chemical treatment, the remaining malignant cells return in three years as metastatic breast cancer and kill the patients. Presently, there is no cure. If there is a family history of an inherited disease in a woman’s family, several reproductive technologies can help prevent the transmission of genetic defects If your mother or her sister or any member of your family died of breast cancer, you are most likely to inherit the mutated BRCA1 or BRCA2 genes
responsible for causing breast cancer. Now, we have sequenced the entire human genome, it is easy to identify the deleterious genes in embryo before conception. The following two genes are associated with breast cancer: BRCA1: gene is located on Chromosome 17 (at position 17q21). Chromosome-17 is a very long chromosome. It is made of 92 million base pairs (AT & GC) and carries 1,394 genes. On the other hand, the BRCA2: gene is located on Chromosome 13 (at position 13q12.3). Chromosome 13 is also a very large chromosome and it is made of 114 million base pairs (AT & GC) and carries 496 genes. The only way to have children free from breast cancer is to conduct the genetic analysis of your embryo. Soon after conception, the fertilized ovum becomes an 8-cell embryo within 3-days. Each cell contains the complete genome. The genome is made of 4-nucleotides (AT & GC), the bio bricks of life. They are not alive because they can be frozen in liquid Nitrogen at 70 degrees below zero for years. When needed, it could be thawed and implanted in the womb. Once implanted in the womb, these bio bricks organized themselves to become alive. Sequencing each cell and comparing it with the Reference Sequence (described below) will help us eliminate any deleterious mutation. Only cells free from all mutations including BRCA1 or BRCA2 will be implanted. As the cost of sequencing is coming down, from the 8-cell embryo, we can sequence each cell cheaper and faster. The child born after the genetic analysis is sure to be free from Breast Cancer causing genes. The only guaranteed cure from breast cancer can be achieved by genetic analysis of the mother, her egg, her ovum and her embryo. The major source of transmission of breast cancer of mutated BRCA1 and BRCA2 from mother to daughter can be eliminated. Despite all precautions to remove deleterious mutations from the cell, we must continue to develop new drugs to treat breast cancer. Despite all precautions to remove deleterious mutations from the cell, we must continue to develop new drugs to treat breast cancer. There are other factors which cause breast cancer such as exposure to radiation, chemical or environmental pollution and viral infection.
