Cystic Fibrosis is caused by a mutation in a gene that encodes cystic fibrosis transmembrane conductance regulator (CFTR) protein, which is expressed in many epithelial and blood cells.

The primary function of the CFTR protein is as an ion channel that regulates liquid volume on epithelial surfaces through chloride secretion and inhibition of sodium absorption [5]. It is also involved in bicarbonate-chloride exchange. A deficiency of bicarbonate secretions leads to poor solubility and aggregation of luminal mucins [6].

Decreased hydration of mucus makes it stickier to bacteria, resulting in infection and inflammation as well as obstruction of glandular ducts. It also results in viscid secretions in the respiratory and Gastrointestinal (GI) tract, pancreas, sweat glands and other exocrine tissues. The increased viscosity of these secretions makes them difficult to clear.

Over 2 million people in the UK carry the defective gene; however the disease is inherited as an autosomal recessive disorder with a rate of 1 in 2500-3500 births.