Cystic Fibrosis Research Paper
Cause of Cystic Fibrosis
Cystic Fibrosis is caused by a mutation in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene. The CFTR gene codes for the CFTR protein which is a chloride ion channel belonging to the ABC (what does it stand for) transporter superfamily of proteins. The CFTR proteins are normally located on the apical plasma membrane of epithelial cells in the airways, lungs, skin, digestive organs (E.g. - the pancreas and intestine) and reproductive tracts (E.g. - sperm duct). The CFTR ion channel allows the movement of chloride ions out of the cells, which then leads to the diffusion of sodium ions out of the cells. Since the electrolyte concentration increases outside the cell, water will also move out of the cell …show more content…
There are “over a thousand” different mutations that could occur in the CFTR gene, these mutations have been organised in to 5 different classes:
(reference table)
Having said that, the most common mutation observed is the deletion of phenylalanine in position 508 (ΔF508), which is seen in around 90% of Cystic Fibrosis patients (reference).
Cystic Fibrosis is an autosomal recessive disease, which means the defective gene must be inherited from both parents in order to be affected. However, findings show that around 1 in 25 people are carriers of the defective gene (reference).
Although carriers of the faulty CFTR gene are not affected by cystic fibrosis, it is thought that they have a ‘heterozygote advantage’. For example, they are resistant to Typhoid and Cholera – diseases that involve the loss of body fluid (reference). This may explain why Cystic Fibrosis is most common in people of European descent, since in the past Cholera and Typhoid were prevalent in Europe. This meant that due to the selective pressures, the carriers of the mutated CFTR gene were more likely to survive and reproduce, resulting in the high frequency of this allele in the
Cystic Fibrosis is caused by a mutation in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene. The CFTR gene codes for the CFTR protein which is a chloride ion channel belonging to the ABC (what does it stand for) transporter superfamily of proteins. The CFTR proteins are normally located on the apical plasma membrane of epithelial cells in the airways, lungs, skin, digestive organs (E.g. - the pancreas and intestine) and reproductive tracts (E.g. - sperm duct). The CFTR ion channel allows the movement of chloride ions out of the cells, which then leads to the diffusion of sodium ions out of the cells. Since the electrolyte concentration increases outside the cell, water will also move out of the cell …show more content…
There are “over a thousand” different mutations that could occur in the CFTR gene, these mutations have been organised in to 5 different classes:
(reference table)
Having said that, the most common mutation observed is the deletion of phenylalanine in position 508 (ΔF508), which is seen in around 90% of Cystic Fibrosis patients (reference).
Cystic Fibrosis is an autosomal recessive disease, which means the defective gene must be inherited from both parents in order to be affected. However, findings show that around 1 in 25 people are carriers of the defective gene (reference).
Although carriers of the faulty CFTR gene are not affected by cystic fibrosis, it is thought that they have a ‘heterozygote advantage’. For example, they are resistant to Typhoid and Cholera – diseases that involve the loss of body fluid (reference). This may explain why Cystic Fibrosis is most common in people of European descent, since in the past Cholera and Typhoid were prevalent in Europe. This meant that due to the selective pressures, the carriers of the mutated CFTR gene were more likely to survive and reproduce, resulting in the high frequency of this allele in the