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Delta F508 and 2184insA

What percentage of the CF population has this genetic mutation? What class is it? What are its symptoms usually look like?
Dear questioner,
In middle and northern Europe, the delta F508 accounts for approximately 70% of CF mutations and is therefore the most frequent CF mutation. I could not find corresponding data on 2184insA, which is much more seldom than delta F508. I looked up the huge CFTR2 database, there 32.834 people with at least one copy of deltaF508 are listed, whereas 132 patients are listed with at least one copy of 2184insA. About 93 patients are reported in that database that carry delta F508 and 2184 insA. This gives you a rough overview about the possible frequency in the population.
There are over 1800 known mutations of the CFTR gene (the cystic fibrosis gene) that are grouped into six classes according to the way they affect the synthesis or functioning of the CFTR protein which serves as an ion channel in the cell membrane. Class I-III mutations result in defective synthesis, processing, maturation and regulation of the CFTR protein with an abolished function of the ion channel. Class IV-VI mutations result in defective conductance, reduced function/synthesis and increased degradation of the CFTR protein, though still with a residual expression and function of the ion channel.
When a patient has a mutation of a different class in each of his/her two CFTR genes, the less severe mutation affects the functioning of the protein and therefore part of the clinical expression of cystic fibrosis. In general, patients with two mutations from class I-III exhibit a phenotype associated with pancreatic insufficiency and a more severe course of the disease compared to patients with at least one class IV-VI mutation. Class IV-VI mutations are usually associated with pancreatic sufficiency and milder lung disease. However, the classification of mutations is not always conclusive and possible.
In your case, both mutations belong to class I-III; delta F508 is a class II mutation as it results in defective maturation of the protein; 2184insA is a so-called frame-shift mutations, that means that large parts of the protein are defect, resulting in defective synthesis of the protein (class I).
You can even find more information about clinical data of patients with these 2 mutations under:

However, mutation analysis only gives a rough direction but it has to be clearly stated that the individual clinical course and especially the degree of lung involvement cannot be predicted according to the genotype, as many other genetic (modifier genes, etc.) and environmental factors play a role and the severity of disease differs substantially even between patients with the exact same mutations. Therefore, it is very important that the individual patient is seen regularly in a certified CF center and follows his individual treatment program.
Yours sincerely,
Dr. Daniela d’Alquen (coordinator of the Central English Archive of ECORN-CF)
Castellani et al in the Journal of Cystic Fibrosis 7 (2008) 179-196: "Consensus on the use and interpretation of cystic fibrosis mutation analysis in clinical practice"
The answer is edited by: Katherine O'Neill