Explaining Cystic Fibrosis

Cystic Fibrosis or CF is a genetic condition, where the body isn’t able to make the secretions it makes watery enough. This means that any body part that makes these secretions, such as the lungs, the pancreas and the intestines can run into trouble with thick, sticky mucus. This is why people with CF often have recurrent chest infections, and tummy problems.

In short, not very. Around 1 in 2500 people are affected. Because you receive a copy of DNA from your mum, and a copy from your dad, both of these copies have to be defective for CF to occur. This means your parents are both ‘carriers’ – they have one defective gene, but they don’t have symptoms because the other copy is working fine. Approximately 1 in every 25 people is one of these ‘carriers’ of the defective gene.

*Here I would draw a diagram about recessive inheritence*

When two people conceive a child, that child receives one of the mother’s genes, at random, and one of the father’s. This means that there are four possible combinations for this gene – Fine/Fine, Fine/defective, defective/Fine, and defective/defective. CF occurs when both are defective, so there is a 25% chance that two carrier parents will have a child with CF.

Usually CF is picked up quite early on, as the baby will have recurrent chest infections, and they may struggle to put on weight as well. They may also be wheezy or short of breath, and have diarrhoea. It is usually detected as part of a screening programme for all babies, though, called the heel prick test. We also have a ‘sweat test’ and genetic tests available to diagnose the condition in older children.

There was no way without both you and your partner being specifically genetically tested that you could have known you had the genes, and even then there was only a 25% that your child was affected. There was nothing that you could have done to make it more or less likely.

Currently there is no cure for the condition, so the main focus is on dealing with the problems that may arise. This includes using antibiotics to prevent chest infections, medicines to help open up the airways and shift the sticky mucus, and providing dietary advice and nutritional supplements to help their growth and development.

The problem with the sticky mucus and the repeated infections is that it takes its toll on the lungs, and they become progressively more damaged over time, making CF a progressive condition. Currently the only treatment for this that we have is a lung transplant. Currently the life expectancy for people with CF is that over half will live beyond 40, however we anticipate that those children born with it now will live longer than this.

Ensuring your child eats well and does regular exercise is the best thing you can do, as they will need more calories and the exercise will help shift the mucus. Making sure nobody in the home is smoking, and generally reducing exposure to pollution and smoke will help reduce infections, as will making sure people at home are washing their hands regularly.

Since you have had one child with CF, we know both you and your partner are carriers. This means any future child also has a 1/4 chance of the condition, however new techniques such as IVF allow us to select embryos that are not affected. Clearly that’s another conversation to have on another day, but there are certainly options.

I’ll get you a leaflet with all the things we’ve discussed, and it also has some useful websites and contact information should you like more information. There are huge amounts of information online, as well as support groups including the Cystic Fibrosis Trust so it’s definitely worth looking it up, and if you have any other questions do feel free to get in contact with us again and we’d be happy to help.