A glimpse into CF

Source:  A glimpse into CF    Tag:  what chromosome is cystic fibrosis found on
So, what exactly is Cystic Fibrosis?
Cystic Fibrosis, commonly referred to as CF, is a hereditary disease that attacks the lungs and digestive system (“What Is Cystic Fibrosis,” n.d.). The protein product of a defective gene creates a high intracellular level of salt, leaving too little extracellular nutrients which are needed to prevent sticky mucus from coating the lungs. These thick, sticky mucus layers make it extremely difficult for CF patients to clear out their lungs and they often feel as though their mucus is suffocating them. Since CF is a chronic disease, meaning it is constantly reoccurring, it leads to serious infections and eventually a state termed multisystem failure because multiple organs lose their ability to function (“What Is Cystic Fibrosis,” n.d.).

Figure 1. This diagram shows the cross section of a normal and CF airway, revealing how mucus obstructing the airway leads to detrimental effects, such as, infections and lung damage. Visual from pathologyproject.wordpress.com

There are cases of CF dating as far back as the Stone Age and descriptions in children’s almanacs warning that 'the child will soon die whose forehead tastes salty when kissed’ (“History of cystic fibrosis,”n.d.). For a long period of time, there was very little information known about CF and it wasn’t until 1953 when Paul di Sant'Agnese was able to provide concrete evidence proving people with CF have an increased salt content in their sweat. In the 1960’s CF organizations, including the Cystic Fibrosis Trust, was established to raise funds for research in finding a cause and cure for CF. Researchers identified chromosome 7 as the gene causing cystic fibrosis in 1985 due to medical technological advances and generous donations. Soon after this discovery, Professor Lap-Chi Tsui, Dr Francis Collins and Professor Jack Riordan were able to pinpoint the specific faulty gene responsible for cystic fibrosis (“History of cystic fibrosis,”n.d.).
In 1985, the cause of CF was identified as a mutation in a gene called the cystic fibrosis transmembrane conductance regulator (CFTR) ( http://ghr.nlm.nih.gov/gene/CFTR). The CFTR gene functions as a channel across the membrane of cells and produces sweat, mucus, and other digestive enzymes. The flow of chloride ions in and out of cells helps control the movement of water in tissues, which is important in the production of thin mucus. When mutations occur in the CFTR gene, it obstructs the chloride channel by preventing the flow of chloride ions and water in and out of cells. As a result, cells that line essential organs, such as, the lungs and pancreas, are covered by think layers of mucus ( http://ghr.nlm.nih.gov/gene/CFTR).

Figure 2. This is an x-ray of a child's lungs with CF. The thick white accumulations on the lungs reveal how excess mucus hinders an individual's lungs from functioning properly.(http://www.columbialungtransplant.org/news_cf_2007.html) 
CF Statistics
v  CF affects about 30,000 children and adults in the United States and 70,000 worldwide
v  About 1,000 new cases of CF are diagnosed yearly
v  More than 70% of patients are diagnosed by age two
v  1 in every 31 Americans is a carrier of at least one copy of the CF gene
v  The median age of survival for individuals with CF is in their early 40’s

People with CF can display a variety of symptoms depending by the type of gene mutation an individual has because there is an assortment of 1,400 mutations (“What Is Cystic Fibrosis? What Causes Cystic Fibrosis,” 2009). Common symptoms among CF patients include: salty tasting skin, wheezing or shortness of breath, poor growth despite good appetite, persistent coughing, and chronic lung infections, such as, bronchitis. In addition, CF is also associated with other conditions like diabetes and infertility.
There are several ways a doctor can test for CF. Most diagnostic tests are performed on infants so doctors can begin early treatment to increase their growth, lung health, and life span. All states in the United States screen newborns for CF, and additional tests, such as, a sweat test, are performed to confirm CF if a child is suspected of having the defective CFTR gene. A sweat test is one of the best ways to diagnose CF and it is relatively simple to do. Small electrodes placed on the skin stimulate sweat glands to produce sweat and high levels of chloride in the sweat are indicative of CF. Doctors can also take a blood or cheek cell sample to analyze for an array of genetic mutations, including CF (“What Is Cystic Fibrosis? What Causes Cystic Fibrosis,” 2009).



Works Cited

History of cystic fibrosis. (n.d.). - Cystic Fibrosis Trust. Retrieved January 19, 2014, from https://www.cysticfibrosis.org.uk/about-cf/what-is-cystic-fibrosis/history-of-cf.aspx

What Is Cystic Fibrosis? What Causes Cystic Fibrosis. (2009, April 28). Medical News Today. Retrieved January 20, 2014, from http://www.medicalnewstoday.com/articles/147960.php