CFTR and autosomal recessive disease: CF is an autosomal recessive disease [3] caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, which encodes a chloride channel regulated by adenosine triphosphate (ATP) and 3 ́,5 ́-cyclic adenosine monophosphate (cAMP) [4], [5].