A cell mutation is an accidental change in the genetic code, or DNA. Most mutations cause a protein to be missing or malformed. Some genetic mutations are inherited, while others occur as a result of environmental factors, such as UV radiation, viruses or chemicals. Many mutations are silent, causing no apparent effect. Others are beneficial and help to keep the gene pool diverse and population health. Most mutations we hear of, however, are those that cause disease.
Sickle Cell Disease
Sickle cell disease is an inherited disease caused by a mutation in a single gene. The mutation causes the body to produce abnormal hemoglobin, which is the protein in red blood cells responsible for carrying oxygen. The abnormal hemoglobin causes the red blood cells to be sickle-shaped, like a crescent, which makes it difficult to move smoothly through the blood vessels. This causes blockages in the vessels resulting in decreased blood flow to areas of the body.
In addition, the abnormal red blood cells have a shorter life span, only about 16 days compared to 120 days of normal red blood cells. This results in a decrease in red blood cells as new ones cannot be produced fast enough to replace those dying out. This condition, known as anemia, causes symptoms of shortness of breath, dizziness, headaches, pale skin and chest pain.
Cystic Fibrosis
Cystic fibrosis is an inherited disease that affects approximately 30,000 children and adults, according to the Cystic Fibrosis Foundation. This disease is caused by a mutation in a single gene that results in a defective protein. This protein induces the body to produce unusually thick, sticky mucus. The presence of this mucus can result in life-threatening lung infections and inhibit the body's ability to break-down and absorb nutrients from food.
The thick mucus in the lungs will cause a persistent productive cough, wheezing and shortness of breath. Because the mucus inhibits the absorption of nutrients, patients will often exhibit poor growth and their stools may be greasy and bulky making bowel movements difficult.
Tay-Sachs Disease
Tay-Sachs disease, also an inherited disease, is caused by a single gene mutation that results in a defective enzyme called beta-hexosaminidase A. This enzyme is responsible for inducing the breakdown of a fatty substance in the brain called ganglioside. The defective enzyme does not perform its duty effectively resulting in a build-up of this fatty substance in the tissues and nerve cells in the brain. This causes deterioration in both mental and physical abilities. Children born with Tay-Sachs disease usually die by the age of 4, according to the National Institute of Neurologic Disorders and Stroke.
Cancer
Cancer is the abnormal growth of cells. As we go through our daily lives, our cells are continually exposed to environmental factors that can cause mutations in our genes. Some genes trigger the division and growth of cells, while others function to control the division of cells. If just the right mutation occurs in just the right gene, it can trigger the uncontrollable growth of cells. The type of cancer induced depends upon the location, the type of cell and the type of mutation.
