Question: what is cystic fibrosis?

Chandrika Nair answered on 15 Jun 2011:

Cystic fibrosis (CF) is the most common inherited disease in the UK. In the UK as a whole, around 1 in 25 people are carriers of the CF mutation and 1 in 2500 babies are born with the disorder. CF is actually most common in Ireland, where 1 in 19 people are carriers of the mutation (carriers don’t suffer from CF but if two carriers have children together, there is a 1 in 4 chance that the child will have the disease).

You might find the idea of mucus quite disgusting but in healthy people it plays the important role of ejecting lots of harmful germs from our lungs and nose. It acts a bit like a conveyor belt or an escalator that stops bacteria from settling down and making us ill.

The problem with CF patients is that they make thick, sticky mucus that can’t eject the bacteria. Essentially, the ‘escalator’ is stuck. This means that they get lots of bacterial infections, some of which can last over 20 years (!), and these are the major cause of death (average life expectancy of CF patients is 35).