The Tragedy of the Cystic Fibrosis Cure

"Woe to the child who tastes salty from a kiss on the brow, for he is cursed and soon will die." That ominous piece of folklore dates back at least to medieval times, and we now know that it likely referred to children with cystic fibrosis.

For most of human history, cystic fibrosis was a death sentence. But in the last few years, scientists have developed drugs so effective that for some, they basically reverse the disease. These new treatments have dramatically improved the lives of 90

percent of patients with the disease. Maybe you can see the problem, though. About 10 percent of cystic fibrosis patients have genetic mutations that these miracle drugs do nothing to fix. So scientists are hunting for a solution that will make

up the difference. Here’s what the future might hold for these salty babies. [♪INTRO] While cystic fibrosis has been around for centuries, it only got its name in the 1930s, when pathologists observed fibrous cysts in pancreas samples taken from children sick with

a then-undefined illness. And while it was first noticed in the pancreas, cystic fibrosis causes problems pretty much everywhere in the body. The disease is caused by mutations in the gene that makes a certain protein in the outside membrane of your

epithelial cells. And it’s a very important protein, because it controls salt and water levels in those cells. When that protein doesn’t work the way it should, your cells can’t hold onto the salt they need and it

just kinda leaks out, hence the salty babies. This is very, very bad. People with cystic fibrosis have issues with electrolyte balance, staying hydrated, and crucially, they have really messed up mucus. You probably don’t think about your mucus very much unless

you’ve got a cold. But you have it all over the place in your body, and it plays a major role in the function of a lot of organs. Including our lungs.

You have a nice layer of mucus coating the inside of your lungs, where it helps trap pathogens and particles before they can damage the lungs and be absorbed into your bloodstream, and then you can cough it out. But crucially, that mucus needs to be thin enough that

it won’t clog up the works, so to speak. People with cystic fibrosis have mucus that’s thick and tar-like, and they basically can’t expel it from their lungs at all. So all those pathogenic baddies that get stuck in the

mucus just… stay there, which means that people with cystic fibrosis often get really nasty lung infections. And if you have all these infectious bacteria trapped in your lungs, you’re pretty darn contagious, and these infections are most dangerous if they spread to other people with cystic

fibrosis. Which means that cystic fibrosis patients have been social distancing before it was cool – they’ve had to, so they don’t make each other sicker. Because the lungs can’t clear out the excess mucus on

their own, one long-term cystic fibrosis treatment is manual percussion therapy, AKA pounding on the chest to try and knock this mucus loose. Every day. Several times a day.

But remember, you have mucus in more places than just your lungs. It’s in lots of other organs too, including the pancreas, as we saw with those first documented cases in the 1930s.

That too-thick mucus blocks up the pancreas, which stops the enzymes made there from getting into your small intestine, meaning that digestion gets all messed up. So people with cystic fibrosis need to take medications with digestive enzymes to correct this.

It can even cause fertility issues, because again, mucus is everywhere, including the lining of the cervix. And cystic fibrosis is caused by a mutation in just a single gene, which was identified in 1989. Scientists called it cystic fibrosis transmembrane conductance regulator gene, or