genetics and pathophysiology
Last edited 08/2022 and last reviewed 08/2022
The defective protein is a cAMP-regulated chloride channel called the cystic fibrosis transmembrane conductance regulator (CFTR) whose gene is on the long arm (q) of chromosome 7. This defective channel leads to a high concentration of sodium and a low concentration of chloride in exocrine secretions (1).
There are many types of defect in the gene, of which the most common, a deletion of phenylalanine at position 508 (ΔF508), accounts for about 70% of the total (1).
The clinical severity of cystic fibrosis varies between patients with the same mutation in CFTR. This suggests that there may be modulator genes which interact with CFTR.
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