This means there is a 3 out of 4 chance that additional children won't have CF. But these children may be carriers of the CF gene. Most often, a family has no history of CF. So the diagnosis comes as a surprise to parents. Or that they passed the gene to the unborn baby at the same time. Genes are found on structures in the cells of the body called chromosomes. Each cell normally has 46 total chromosomes, or 23 pairs of chromosomes.
The seventh pair of chromosomes has a gene called the CFTR cystic fibrosis transmembrane conductance regulator gene. Changes mutations or errors in this gene are what cause CF. This gene is very large and complex. More than 1, different mutations in this gene have been found that cause CF. According to the Cystic Fibrosis Foundation, if you have no family history of CF, the risk of having a mutation in the gene for CF depends on your ethnic background:.
Some affected babies have meconium ileus, a blockage of the intestine that occurs shortly after birth. Other digestive problems result from a buildup of thick, sticky mucus in the pancreas. The pancreas is an organ that produces insulin a hormone that helps control blood sugar levels.
It also makes enzymes that help digest food. In people with cystic fibrosis, mucus often damages the pancreas, impairing its ability to produce insulin and digestive enzymes.
Problems with digestion can lead to diarrhea, malnutrition, poor growth, and weight loss. In adolescence or adulthood, a shortage of insulin can cause a form of diabetes known as cystic fibrosis-related diabetes mellitus CFRDM. Cystic fibrosis used to be considered a fatal disease of childhood. With improved treatments and better ways to manage the disease, many people with cystic fibrosis now live well into adulthood. Adults with cystic fibrosis experience health problems affecting the respiratory, digestive, and reproductive systems.
Most men with cystic fibrosis have congenital bilateral absence of the vas deferens CBAVD , a condition in which the tubes that carry sperm the vas deferens are blocked by mucus and do not develop properly.
Women with cystic fibrosis may experience complications in pregnancy. Cystic fibrosis is a common genetic disease within the white population in the United States. The disease occurs in 1 in 2, to 3, white newborns.
Cystic fibrosis is less common in other ethnic groups, affecting about 1 in 17, African Americans and 1 in 31, Asian Americans. Mutations in the CFTR gene cause cystic fibrosis. The CFTR gene provides instructions for making a channel that transports negatively charged particles called chloride ions into and out of cells.
Chloride is a component of sodium chloride, a common salt found in sweat. Chloride also has important functions in cells; for example, the flow of chloride ions helps control the movement of water in tissues, which is necessary for the production of thin, freely flowing mucus. Mutations in the CFTR gene disrupt the function of the chloride channels, preventing them from regulating the flow of chloride ions and water across cell membranes.
For this reason, avoiding germs is a top concern for people with CF. In the pancreas , the buildup of mucus prevents the release of digestive enzymes that help the body absorb food and key nutrients , resulting in malnutrition and poor growth.
In the liver, the thick mucus can block the bile duct, causing liver disease. In men, CF can affect their ability to have children. Today, because of improved medical treatments and care, more than half of people with CF are age 18 or older. Many people with CF can expect to live healthy, fulfilling lives into their 30s, 40s, and beyond. Read the Foundation's Patient Registry Reports. Cystic fibrosis is a genetic disease. People with CF have inherited two copies of the defective CF gene -- one copy from each parent.
Both parents must have at least one copy of the defective gene. People with only one copy of the defective CF gene are called carriers, but they do not have the disease. Each time two CF carriers have a child, the chances are:. The defective CF gene contains a slight abnormality called a mutation. There are more than 1, known mutations of the disease. Most genetic tests only screen for the most common CF mutations. Therefore, the test results may indicate a person who is a carrier of the CF gene is not a carrier.
Diagnosing cystic fibrosis is a multistep process, and should include a:. Although most people are diagnosed with CF by the age of 2, some are diagnosed as adults. A CF specialist can order a sweat test and recommend additional testing to confirm a CF diagnosis.
Cystic fibrosis is a complex disease. The types of symptoms and how severe they are can differ widely from person to person. Many different factors can affect a person's health and the course the disease runs, including your age when you are diagnosed.
Tremendous advancements in specialized CF care have added years and improve the quality of the lives of people with cystic fibrosis. During the s, a child with CF rarely lived long enough to attend elementary school.
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