Cystic Fibrosis

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Introduction:

Cystic fibrosis (CF) also known as mucoviscidosis is an inherited disease that causes the body to produce mucus that's extremely thick and sticky. The mucus in people with CF is thicker than normal because CF affects cells in the epithelium, the layer of cells that lines the passages in the body's organs. In a person who does not have CF, the epithelial cells produce a thin, watery mucus that acts like a lubricant and helps protect the body's tissues. In a person with CF, however, the thicker mucus doesn't move as easily. This thick, sticky mucus clogs passages in many of the body's organs and infection sets in.

The two organs that are most affected are the lungs and pancreas, where the thick mucus causes breathing and digestive problems (Warrell,2003). The thicker mucus has trouble moving out of the lungs, so bacteria can remain and cause infections. The thick mucus can also be found in the pancreas — an organ that produces proteins called enzymes that flow into the intestine to support the body's digestion process. Because the mucus can block the path between the pancreas and the intestines, people with CF have trouble digesting food and getting the vitamins and nutrients they need from it (Warrell,2003). CF can also affect the liver, the sweat glands, and the reproductive organs (McPherson & Pincus,2006). Cystic fibrosis is caused by mutations (changes) in a gene on chromosome 7, one of the 23 pairs of chromosomes that children inherit from their parents. Cystic fibrosis occurs because of mutations in the gene that makes a protein called CFTR (cystic fibrosis transmembrane regulator) (Warrell,2003). A person with CF produces abnormal CFTR protein — or no CFTR protein at all, which causes the body to make thick, sticky mucus instead of the thin, watery kind. People who are born with CF have two copies of the CF gene. In almost all people born with CF, one gene is received from each parent. This means that the parents of kids with CF are usually both CF carriers — that is, they have one normal and one defective gene — but the parents may not have CF themselves because their normal gene is able to "take over" and make the necessary CFTR protein(McPherson & Pincus,2006). Each child born to parents who are both CF carriers has a 1 in 4 chance of having the disease. Cystic fibrosis occurs most frequently in Caucasians of northern European descent, in whom the CF gene is most common — although people of other heritages can get the disease, too (McPherson & Pincus,2006). People who have a close relative with CF are also more likely to carry the CF gene — approximately 12 million Americans, or 1 in every 20 people living in this country, is a CF carrier and most of them don't know it (www.cff.org). Parents can be tested to see if they carry the CF gene, but because there are hundreds of specific CF gene mutations (not all of which are known), genetic testing for CF won't detect everyone who is carrying a CF gene. Doctors can also perform tests during pregnancy so prospective parents can find out more about the chances that their child will have CF. However, these tests also won't always detect a CF gene. Based on statistics, there is 1 in every 1600 Caucasian births and 1 in 17 000 African American births has a CF incidence(McPherson & Pincus,2006). Approximately 1 in every 20 Caucasians is a carrier. Cystic Fibrosis is the #1 genetic killer of children and young adults in the United States. Also, 1 in 20 Americans - more than 12 million - is an unknowing, symptomless carrier of the disease. Whether male or female everyone is equally likely to inherit CF. Worldwide, about 70,000 people have cystic fibrosis. Ninety percent are diagnosed before the age of 17(www.cff.org). A documented history of CF can be traced in the 1930s. Prior to that, most cases of CF were misdiagnosed as hard coughs, pneumonia or chronic bronchitis. However, people in the 18th century were already aware of what CF...
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