Hello and welcome to the Zero to Finals podcast.

My name is Tom, and in this episode I'm going to be talking to you about cystic fibrosis.

And if you want to follow along with written notes on this topic, you can follow along at

0.0.0.com slash cystic fibrosis or in the respiratory section of the zero to finals pediatrics book.

So let's get straight into it.

Cystic fibrosis, or CF, is an autosomal recessive genetic condition that affects the mucus glands.

It's caused by a genetic mutation of the cystic fibrosis trans membrane conductance

regulated gene on chromosome 7.

And there are many variants of this mutation and the most common is the Delta F508 mutation.

This gene codes for cellular channels, particularly a type of chloride channel.

Around 1 in 2,500 children have cystic fibrosis, and about 1 in 25 people in the UK are carriers of the mutation.

The key consequences of the cystic fibrosis mutation are thick pancreatic and bilary secretions

that cause blockage of the ducts and this results in a lack of digestive enzymes such as pancreatic

lipase in the digestive tract.

Low volume thick airway secretions that reduce airway clearance resulting in bacterial colonization

and susceptibility to airway infections,

and congenital bilateral absence of the vast deference in males.

Patients generally have healthy sperm, but the sperm have no way of getting from the testes to the ejaculate,

and this results in male infertility.

A quick Tom tip for you, cystic fibrosis is a very common exam topic,

and a favourite of examiners to test your knowledge of genetic inheritance.

Remember that cystic fibrosis is autosomal recessive? And a popular scenario in your exams is that both

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