Cystic Fibrosis is an autosomal linked recessive genetic disorder that affects mainly lungs and occasionally other organs such as liver, kidney, pancreas, intestine etc.
The word Cystic Fibrosis is derived from two words cysts and fibrosis.
A cyst is a closed sac having a distinct membrane & division compared to nearby tissue.
A Fibrosis is the formation of excess fibrous connective tissue in an organ or tissue in a reparative or reactive process.
Cystic fibrosis is caused due to improper functioning of a protein known as CFTR (Cystic Fibrosis Transmembrane Regulator). Normally, being an integral protein CFTR plays an important role as an ion channel. By using ATP ( energy currency of cell), it helps transport Chloride and thiocyanate ion [SCN]− out of the epithelial cells ( outermost cells of the body that line major cavities) to the nearby surrounding mucous. Thus, by increasing the electrolytic concentration ,it helps in movement of water by osmosis. Basically CFTR is involved in production and regulation of sweat, digestive fluids and mucous. A mutation of both genes present in the long arm of Chromosome 7 render the CFTR useless resulting in these secretions becoming thick , due to none or reduced movement of both Cl- and [SCN]− ions.
It is generally identified by Sweat test and Genetic testing.
Most common cause is the deletion of a codon for an amino acid Phenylalanine at 508th position (technically CFTRΔF508)
People with Cystic Fibrosis sweat a lot. In addition to it, they cough out a profusion of mucous and phlegm and in some cases, blood. Other main symptoms include, salty tasting skin, poor weight gain, poor growth, chest infection and infertility in males. It is one of the most common diseases in Northern Europe. It was first discovered by Dorothy Anderson. Approx. 80% of the people suffering from cystic fibrosis develop lung problems.
Inability to pass meconeum (meconeum illeus) in new borns is a very common sign of cystic fibrosis.
Meconium is the first stool of an infant and contains epithelial cell, lanugo, mucous, amniotic fluid, bile etc. It is dark olive-green in colour
Lanugo is unpigmented soft downy hair found on foetus
As already mentioned, Cystic Fibrosis can occur in many internal organs of the body like liver , lungs , intestine etc. Lets look at how this disease affects one’s internal organs :-
#Cystic Fibrosis of Lungs
- Pulmonary Hypertension – High blood pressure in the lungs.
- Bronchietasis – abnormal widening of bronchi or bronchioles
- Haemoptysis – coughing up blood
- Hypoxia – body deprived of oxygen supply
- Allergic bronchopulmnary aspergillosis – allergy to the common fungus aspergillus.
#Cystic Fibrosis of Pancreas
- Pancreatitis – inflammation of the pancreas
- Atrophy Of Exocrine glands
- CFRD – Cystic Fibrosis Related Diabetes
Cystic Fibrosis Related Diabetes is a special type of Diabetes that occurs due to destruction of the cells of Islets of Langerhans of pancreas in Cystic fibrosis patients.
Islets of Langerhans are the endocrine part of pancreas which contains cells that secretes Insulin and glucagon, two main enzymes responsible for regulation of blood sugar level
Fibrosis of the cells of pancreas leads to less or no production of pancreatic juice thereby affecting digestion and absorption of food directly.
#Cystic Fibrosis Of Intestine
Apart from lungs, the most common Cystic fibrosis effected part is the intestines. The symptoms include:-
- Abdominal bloating, cramping, or abdominal pain
- Frequent bulky, greasy or oily, and foul-smelling stools
- Flatulence (excess gas) and poor weight gain.
- Bowel obstruction due to meconeum illeus in infants.
- Intussusception – A condition in which part of intestine invaginates into another section of intestine.
#Cystic Fibrosis Of Liver
- Due to thickening of the bile juice, the bile ducts get blocked causing extreme pain and difficulty in emulsification of fats.
In addition to all these effects on the internal organs, Cystic Fibrosis can also manifest itself as a Coagulation Disorder, by impairing Vitamin K absorption which is responsible for production of clotting factors II, VII, IX, and X.
Like most genetic diseases, it has no cure, but symptoms can be alievated in people suffering from Lung cystic fibrosis by treatment with antibiotics such as Azithromycin or by hypertonic saline drip & Salbutamol,
Lung transplantation is also a viable option for people with severly effected lungs.
Gene therapy is also being viewed as a potential long-term cure but has till now shown only limited results.