Genetics: Unit 9: Molecular Evolution, Population Genetics, and Complex Inheritance - Assignment Example

This has been made possible through the genetic analysis of BRCA1 and BRCA2 tumor suppressor genes that are found in the human breast cells. The two genes are responsible for repairing impaired DNA or alternatively, to kill the breast cells in situations where the DNA cannot be rehabilitated to its functioning state. Either a single strand or the double strand of the DNA normally break and the BRCA genes play a key role to fix the strand breaks. Genes are susceptible to mutations – alterations in their distinguishing sequence (Pierce, 2009).

If a mutation in the BRCA2 or BRCA1 occurs and it damages the genes, the DNA in the breast cells is resultantly left unrepaired thus increasing the chances of occurrence of breast cancer. Mutations in the BRCA 2 and BRCA 1 occur as a result of removal or addition of a small amount of DNA base pairs within the gene. PCR and DNA Sequencing can be used to identify such mutations in the BRCA 2 and the BRCA 1 genes. The Polymerase Chain Reaction procedure amplifies a targeted part of the DNA strand for closer analysis while the DNA sequencing approach identifies the nucleotides that are out of sequence in the DNA molecule.

Due to the mutations, the protein element of the genes which are in the breast cells become abnormal and seizes to function as expected. The defective protein becomes infectious leading to mutations in other genes. This outcome leads to a buildup in mutations over time leading to uncontrolled cell division. The abnormal cells pile up to form a tumor on the breast cells. The tumor is what leads to breast cancer diagnosis. The tumor is manifested externally through the formation of tangible lumps right under the skin of the breast, a dimple on the breast surface, a deformed breast shape or a scaly red patch on the surface of the breast.

The nipple may discharge fluid. Early exposure to chemotherapy may destroy the affected cells. A