CYSTIC FIBROSIS

Cystic Fibrosis

Cystic Fibrosis

Part 1: Background

 

1a) Explain briefly what Cystic Fibrosis is - provide a definition of CF

Cystic fibrosis, or cystic fibrosis, is a genetic disorder that affects the respiratory and digestive tracts. The symptoms appear in childhood and their severity varies from person to person. It is a systemic hereditary disease caused by mutations in the gene cystic fibrosis transmembrane regulator (CFTR) and characterized by lesions exocrine glands, severe functional disorders of the respiratory and gastro-intestinal tract. It is most common among the known hereditary diseases. Every 20th inhabitant of the planet is a carrier of the defective gene. The lungs are often the hardest hit. The thick, sticky secretions obstruct the airways and then the alveoli, making breathing labored (cftrust.org.uk). In addition, the mucus that accumulates in the lungs is an environment conducive to the formation of bacteria.

1b) How do faulty CFTR genes lead to thicker mucus in cystic fibrosis patients?

 This disease causes a thickening of mucus secreted in the sinuses, bronchi, intestine, pancreas, liver and reproductive system (Kerem et al, 1989, pp. 1073). Data on the incidence of cystic fibrosis are variable, on average; it amounts to 1:5000 newborns. Cystic fibrosis is inherited in an autosomal recessive manner. Disease is associated with a mutation in the gene CFTR (Cystic Fibrosis Transmembrane Conductance Regulator, or CFTR - cystic fibrosis transmembrane regulator). Cystic fibrosis gene determines the synthesis of a protein called cystic fibrosis transmembrane conductance regulator. This leads to excessive excretion of chloride, resulting in - hypersecretion of thick mucus in the cells of the endocrine pancreas, the epithelium of the bronchi, the mucous membrane of the gastrointestinal tract. The protein synthesized from the CFTR gene binds to the outer membrane of the cells in sweat glands, lung, pancreas and other organs affected. The protein crosses the membrane and acts as a channel connecting the inside of the cell (cytoplasmic) in the extracellular fluid. This channel is largely responsible for controlling the passage of chloride to (and from) the internal environment. When the CFTR protein does not function properly, this movement is restricted, retaining chloride in the extracellular space (Rosaler, 2007, pp.109).

Part 2: Prevalence and diagnosis of CF

 

2a) How many people carry the faulty gene for CF in the UK?

1 person in every 25 people carries the gene of CF mostly without knowing it in UK. If two carriers are having a baby, the chance of having a baby having Cystic fibrosis is 1 in 5.

 

2b) How many people have the disease?

 There is about 1 in every 2,500 babies in UK that are born with cystic fibrosis. Currently, the numbers are rising in UK, as there are over 9,000 people who have cystic fibrosis. Cystic is an autosomal recessive disorder, which means that it needs to have two inherited cystic fibrosis genes in order to develop, one from the father and one from the mother. If the person carries only one cystic fibrosis gene, then the person is called carrier ...