children s health issues
Cystic Fibrosis (CF)
Causes of Cystic Fibrosis
Cystic fibrosis results when a person inherits two defective copies (variants) of a particular gene, one from each parent. This gene is called the cystic fibrosis transmembrane conductance regulator (CFTR). There are a number of variants of theCFTRgene. For example, the most common one is called the F508del variant. TheCFTRgene controls the production of a protein that regulates the movement of chloride, bicarbonate, and sodium (salt) across cell membranes. Variants of theCFTRgene cause the protein to become dysfunctional. If the protein does not work correctly, the movement of chloride, bicarbonate, and sodium is disrupted, leading to thickening and increased stickiness of secretions throughout the body. Worldwide, about 3 of 100 White people carry one defective copy of theCFTRgene. People with one defective copy are carriers, but they themselves do not get sick. About 3 of 10,000 White people inherit two defective copies of the gene and, as a result, develop cystic fibrosis. Cystic fibrosis affects many organs throughout the body and nearly all the glands that secrete fluids into a duct (exocrine glands). Theorgans most commonly affectedare the Lungs Pancreas Intestines Liver and gallbladder Reproductive organs are normal at birth, but problems can develop at any time afterward as thick secretions begin to block the small airways (mucus plugging). The plugging leads to chronic bacterial infections and inflammation that cause permanent damage to the airways ( Bronchiectasis ). These problems make breathing increasingly difficult and reduce the lungs’ ability to transfer oxygen to the blood. People also may have frequent bacterial respiratory infections that affect the sinuses. blockage of ducts prevents digestive enzymes from reaching the small intestine. A lack of these enzymes leads to poor absorption of fats, proteins, and vitamins ( Overview of Malabsorption ). This poor absorption, in turn, can lead to nutritional deficiencies and poor growth. Eventually, the pancreas can become scarred and no longer produce enough can become blocked by thick secretions. This blockage is common immediately after birth because the contents of the fetus's digestive tract (called meconium) are abnormally thick. Such blockage in the small intestine is called Meconium Ileus and in the large intestine is called can be blocked by thick secretions, which eventually can cause liver scarring ( Fibrosis of the Liver ). Thereproductive organscan be blocked by thick secretions, which can cause infertility. Almost all men are infertile, but infertility is much less common in women. Thesweat glandssecrete fluid containing more salt than normal, increasing the risk of dehydration. 