Genetic Mutations Informative Essay

Julio Hernandez Genetic Mutation is a change of the nucleotide sequence of a genome. Mutations result from un-repaired damage to DNA or RNA genomes usually caused by radiation or chemical mutagens or from errors in the process of replications. Mutations play a part in both normal and abnormal biological processes, including evolution, development of the immune system, and cancer. There are two main types of genes that play a role in cancer, ocnogenes and tumor suppressor genes. An important difference between the two is that ocnogenes result from the activation of proto-ocnogenes, but tumor suppressor genes cause cancer when they are inactivated. Ocnogenes are mutations of certain normal genes called pro to-ocnogenes. Proto-ocnogenes
are the normal or "good" genes that normally control what kind of cell it is and how often it divides. When it mutates it turns into ocnogenes, that can become permanently turned on or activated when it isn 't supposed to be. When this happens the cells grow out of control, which can lead to cancer. A few cancer syndromes are caused by inherited mutations of proto-ocnogenes that cause the ocnogene to be turned on. Multiple Endocrine Neoplasia Type 2 (MEN2) is caused by and inherited mutation in the gene. People affected by this syndrome often develop an uncommon thyroid cancer called medullary cancer of the thyroid. The syndrome also develops other tumors. Most cancer-causing mutations involving ocnogenes are acquired, not inherited. They generally activate ocnogenes by chromosome rearrangements, gene duplication, or mutation. One thing could lead to another and lead to cancers and tumors. Tumor suppressor genes is another main type of gene that plays a role in cancer. Tumor suppressor genes are genes that slow down cell division, repair DNA mistakes, or tell cells when to die. When they don 't work properly, cells can grow out of control, which could in turn lead to cancer. Inhertited abnormalities of tumor suppressor genes have been found in some family cancer syndromes. They cause certain types of cancer to run in families. Again one thing would lead to another. For example, a defective APC gene causes FAP, a condition in which people develop hundreds or even thousands of colon polyps. Often, at least one of the polyps becomes cancer, leading to colon cancer. Cell division is a process during which DNA makes a copy or replica of itself.
During this complex process, mistakes may occur. Mismatch-repair genes are the DNA repair genes that correct these naturally occurring spelling errors in the DNA. When these genes are altered or mutated, however, mistakes in the DNA remain. If these mistakes occur in tumor suppressor genes or proto-ocnogenes, eventually this will lead to uncontrolled cell growth and tumor formation. There are other types of DNA repair genes that repair errors in DNA that occur from mutagenic agents such as large doses of radiation. Mutations in DNA repair genes can be inherited from a parent or acquired over time as the result of aging and environmental exposures. DNA repair genes require two mutations ( both members of the gene pair) in order for the process of tumor formation to occur. It takes mutations in several of these genes for cancer to develop. In most cases of cancer, all the mutations are acquired. In inherited cancer, one mutation is passed down from the parent, but the remainder are required. Since it takes more than a single mutation to cause cancer, not all people who inherit a mutation in a tumor suppressor gene, proto-ocnogene, or DNA repair gene will develop
cancer.

Bibliography: http://cancer.stanford.edu/information/geneticsAndCancer/genesCause.html http://www.cancer.org/cancer/cancercauses/geneticsandcancer/oncogenesandtumorsuppressorgenes/oncogenes-tumor-suppressor-genes-and-cancer-mutations-and-cancer
http://www.cancerresearchuk.org/cancer-help/about-cancer/what-is-cancer/cells/how-cancer-starts