What is cystic fibrosis?|
Cystic fibrosis (CF) is an inherited disorder due to an abnormality in the genetic material in the body cells. It affects many different organs, but major symptoms develop as a result of the disease affecting the lungs and malabsorption problems realted to poor functioning of the pancreas1.
Nearly all exocrine glands of the body are affected. Exocrine glands are clusters of cells producing secretions for normal body function. In CF, the pancreas secretions are abnormally thick and viscus, the lung secretions are made excessively, and there is a high salt content in the sweat. Other glands involved include those in the intestines, salivary glands and the reproductive tract, and these give rise to other problems associated with CF.1
How CF affects the lung function
Studies have shown that damage to the lung in CF occurs after birth due to the abnormally thick mucus secretions causing widespread obstruction and secondary infection of small airways. The walls of the airways become thickened and there may be also partial collapse of the areas of the lung (atelectasis). The blood vessels in the lung has a tendency to narrow when there is a low level of oxygen, this can increase the demand of the heart to push blood through the lungs and heart failure may develop in the final stages of the condition1.
Further damage to the lung are due to the chronic inflammation especially with the development of bronchiectasis (abnormal widening of airways due to destruction of the walls) This can be complicated by secondary bacterial infections with bugs such as staphylococcus aureus and, pseudomonas aeruginosa1.
What causes cystic fibrosis?
CF is the most common genetically inherited disease amongst Caucasians2. It is the result of an abnormality of a gene that dictates the making of a special protein called the cystic fibrosis transmembrane regulator (CFTR).
The human genetic makeup consists of vast number of genes, they are sections of the DNA molecule and dictate how proteins are made. Each individual inherit one form of the gene from each parent. CF is inherited by a recessive fashion, which means that the disorder would occur only if the both genes from each of the parents carries the mutation. Some individuals, who are termed "carriers" are those with an abnormality in only one of the two genes, they do not show signs and symptoms of CF, but there is a chance for it to be passed on to the next generation.
Meconium ileus in the newborn
About one-fifth of babies with CF presents with meconium ileus, which is an obstruction of the gut because the meconium (contents in the gut of newborns) is abnormally thick and unable to be passed3. Other bowel complications may occur, such as volvulus (bowel becoming entangled), perforation
Some infants may have problem gaining weight, can develop anaemia or oedema due to poor absorption of protein from the gut1.
Problems with lung function
Half of CF patients have lung symptoms such as coughing with sputum production, wheezing due to repeated or long term infections. There may be vomiting, disturbed sleep, increasing difficulty in breathing, chest becoming over expanded, episodes of cyanosis ("blue lips or tongue") and nail changes (called clubbing). Complications of the lung problems in CF include pneumothorax (collapse of lung due to an air leak), haemoptysis (coughing up blood) and right heart failure. These complications tend to present in later years
About 90% of CF patients suffer from malabsorption caused by poor function of the pancreas. This give rise to steatorrhea (bulky, foul-smelling, fatty stools), swelling of the abdomen, poor growth pattern, and loss of muscle