One of the leading cystic fibrosis causes is improper coding of the genes. This is a recessive genetic disease that causes cysts and fibrosis of the pancreas as well as lungs. The following article will discuss some information on the cystic fibrosis causes and effects, that will help you know more about this inherited disorder.
Cystic fibrosis (CF) is an inherited disorder of the secretory glands. It is one of the most common life-threatening disorder that affects the people of Caucasian origins. This condition leads to production of excessive mucus clogs in the cells of the lungs, sweat glands as well as digestive tract. Cells in these organs produce thin and slipper mucus. However, when a person is affected with cystic fibrosis, the cells produce very thick and sticky mucus. This mucus does not serve as a lubricant and tends to plug up the tubes, ducts, etc. in the lungs and pancreas.
Thus, leading to damage of the respiratory, digestive and other systems. The cystic fibrosis causes include inheritance of one faulty gene by the child from each parent. There are about 30,000 people affected with cystic fibrosis and in most cases the affected person does not live past their teenage years.
Facts about Cystic Fibrosis
A person is said to be a carrier when he/she carries one gene for cystic fibrosis. The carrier lives a completely healthy and symptom free life. However, when two carriers of the faulty gene have a baby, there are:
- 1 in 4 chance that child may not inherit the disorder, live a symptom free life as well as does not become a carrier of the gene.
- 1 in 2 chance that the child may inherit just one copy of the faulty gene. Thus, the child will not suffer from the condition, but become a carrier of the gene.
- 1 in 4 chance that child inherits both the faulty gene copies from the parents and suffers from cystic fibrosis.
What Causes Cystic Fibrosis?
Cystic fibrosis is caused by a mutation in a particular gene. This gene codes for the protein cystic fibrosis transmembrane conductance regulator (CFTR). The term may be quite a mouthful, but is extremely important for regulation of the components related to sweat, digestive juices as well as mucus.
One requires at least one copy of a functional CFTR gene to remain free from the cystic fibrosis disease. This is because this is an autosomal recessive inherited disease that requires two faulty genes to lead to formation of this condition. CF occurs only when one inherits two copies of the faulty gene present on chromosome 7.
The mutation generally occurs in due to a deletion (ΔF508) of three nucleotides. When this deletion occurs, it leads to loss of an amino acid phenylalanine (F) that is present on the 508th position of the protein. This mutation is seen in almost 2/3rd of the cases of CF around the world. In the United States, this deletion leads to CF in about 90% of the cases.
When there is no mutation in CFTR, it is present on the cell membrane of certain cells. Its function is to control the passage of chloride ions in and out of the cell. In case of mutation, the CFTR does not function as it should and does not open up to allow the movement of the ions. In most of the cases seen in patients from the United States, the CFTR is completely missing from its position on the membrane.
All because three nucleotides, CTT (cytosine and thymine) are missing. Thus, the amino acid phenylalanine misses from its 508th position on the CFTR. This causes the protein structure to be shortened and the cell terms it as an error. So, as the protein is traveling towards the cell’s membrane from the endoplasmic reticulum, the cell destroys the protein, termed as an error. Thus, it remains missing on the cell membrane.
As the protein is missing, it leads to many effects on the body. When it is absent in the sweat glands, it causes the sweat to become saltier than usual. The reabsorption of sodium and chloride ions does not occur and the sweat becomes 5 times saltier than usual. It causes problems with the balance of ions in the blood. In turn, this leads to problems with the normal rhythms of the heart.
When CFRT is missing in the digestive organs like pancreas, it causes blockage of digestive enzymes. They cannot reach the intestines and thus, leading to problems with food digestion. The movement of chloride ions in pancreas is absent and this prevents the water carrying enzymes from the pancreas to enter the intestines. As the enzymes fail to move towards the intestine, they start digesting the pancreas instead.
Thus, the pancreas become inflamed and get plugged by the thick mucus. Lungs are the most affected organs due to CF. It is not exactly clear how CF causes lung damage. The thick mucus present in the lungs makes it susceptible to bacterial infections. The mucus does not clear up from the bronchioles and reduces their capacity to absorb oxygen. On the other hand, the immune cells produced to kill the bacterial infections, accidentally starts attacking the normal lung cells. This leads to maximum lung damage.
What are the Symptoms of Cystic Fibrosis?
The symptoms of cystic fibrosis varies from person to person. The symptoms may be mild and severe and even differ in intensity in the same person with time. Excessively salty skin is the first sign of cystic fibrosis. When parents kiss their children, they find the taste of their sweat or skin is excessively salty than it usually is. Other symptoms depend on the organs affected.
When the respiratory system is affected, it leads to persistent cough, wheezing, recurrent lung infections and sinus infections. When the mucus builds up in the pancreas, it prevents the passage of digestive enzymes to the small intestine. This causes reduction in the absorption of the nutrients from food. This leads to passage of very foul smell, greasy stools. The child suffers from poor weight gain and suffers from slow growth. One may observe distended abdomen due to constipation. Newborns may show signs of intestinal blockage.
What are the Treatment Options Available for Cystic Fibrosis?
This is a genetic disorder and there is no cure for cystic fibrosis. Early detection can help manage the conditions and reduce the complications of this disease. The treatment includes use of antibiotics that helps keep infections at bay. The doctor may prescribe mucus-thinning drugs that help in coughing out the excess mucus in lungs. If digestion of food becomes a problem, a feeding tube may be surgically implanted or threaded through the nose to the stomach to help provide extra nutrition to the body. Blocked bowels may require surgery, especially if death of a part of bowel occurs.
This was all about cystic fibrosis and risk factors. People should get themselves checked for presence of the faulty gene for CF before starting a family. This is especially true in cases if there has been a case of CF in the family. As it is very common in people of European and North American origin, in other words, Caucasians, one should undergo genetic testing. This will help prevent this debilitating condition from being inherited by their children to a great extent.