Pachyonychia Congenita or PC is a rare genetic skin condition. It affects both boys and girls equally and people from all around the world.
First, the words Pachyonychia Congenita are big words. No one really wants to say them or spell them, so we like to call our skin condition PC for short.
This section explains some of the big questions around PC.
The Science Bit
Humans have 19,000-20,000 genes. When parents pass their genes down to their children, it is thought that 60 errors, called mutations, are introduced to the genetic code in the process. Any of those mutations could be the source of major differences in a person’s appearance or behavior compared to his or her parents. It is a nice thought that a genetic mutation might lead to something interesting like being able to fly, or see through walls, but sadly PC is caused by an error in one of five keratin genes, which causes skin problems. Depending on where the mutation is, PC varies in how it looks.
Who gets it?
Anyone!! Because it is a genetic error, any baby born might have PC. The chances are very low. This is called a spontaneous case – it is nothing to do with what your parents may or may not have done. It just happens spontaneously!
However, a much greater chance of having PC is if one of your parents already has it. If this is the case, then there is a 50% chance in each pregnancy of the baby having PC. This explains why, if one of your parents has PC, you may have PC, but your brother or sister might not.
Why is it called PC?
The term Pachyonychia Congenita means thick nails. Pachy means thick and onychia means nails. Some people who have PC have thick nails, but some may only have one thickened toenail and have the rest of their nails flat! The term PC is used to cover errors in one of 5 keratin genes that relate to the skin and might lead to one or more of the appearances described below.
How it looks
Because the general term PC covers errors in 5 different but very related genes, the appearance on the skin can be massively different. Some people have thick nails on their hands and/or feet. Some people have thick skin called calluses on their feet, and sometimes on their hands. Other people have cysts, which may be small or large bumps on or under the skin. Some people may have a combination of all of these features.
Here are some examples of the different appearances for PC. Do you have any of these symptoms?
Can I catch PC?
No! PC is a genetic condition, meaning you can’t catch it from someone else. You either have it or you don’t. It’s also not contagious which means you can’t spread it to your classmates or friends.
How is it different from thick skin that lots of people have?
If you have PC which results in thick skin on your feet, you might have been told that you ‘just have thick skin’, a bit like the type that many people get, especially as they get older. In some respects, this is true as thick skin is a build-up of dead skin cells, but the whole reason behind it is different. This means that there can be lots of pain involved in walking for a person who has PC, but no effect for a person with thick skin who doesn’t have PC.
Is there a cure?
Unfortunately, not yet. There are only ways of treating the symptoms such as the thick skin or thick nails. And so far, PC cannot yet be stopped from happening in the first place. However, lots of work has been carried out trying to understand PC better, what causes it, and how it could potentially be treated to prevent the symptoms. This work is being carried out now by scientists in different locations around the world!