Genes in our chromosomes can sometimes cause alterations in there information. This is caused when cells are ageing or when cells have been exposed to chemicals or radiation. Most of the time the cells recognise these mutations and repair themselves. However other times they stay and cause illness and disorders. If the mutations occur in the sperm or egg cells, children could inherit the disorder. This happens when the mutated gene is inherited from the parent. This is called a genetic disorder. There are more than 4000 diseases caused by genetic mutations. Having a diseased gene does not mean that it will be present in your phenotype. Because we inherit a gene from each parent having one diseased gene does not mean that you will actually have the disease because the normal gene will allow your body to act perfectly normal. On average a person may carry 5-10 mutated genes in there cells. Disorders appear when the mutated gene is dominant or when the mutated gene is present in both chromosomes. Problems also occur when the mutated genes interact with one another or with environment. If a person carries a dominant mutated gene he or she will usually have the disease. The person's children will have a 50% chance of inheriting the disease. If a person carries a recessive mutated gene he or she is a carrier but is normal. When two carriers have a child, the child has a 25% chance of inheriting the disease. Cystic Fibrosis or CF is a recessive disease gene from both parents coming together in a child.
Cystic Fibrosis is an inherited disease that causes the body to produce a thick and sticky mucus. This mucus clogs the passage of many of the body's organs. It can affect the lungs, liver pancreas, sweat glands and the reproductive organs. However cystic fibrosis mainly affects the lungs and pancreas which causes serious breathing and digestive problems. .
In a person without cystic fibrosis the cells in the epithelium, the outer lining of the body passages produce a thin watery mucus which acts like a lubricant.