Pachyonychia Congenita (PC) is a rare genetic skin disorder that affects people of all backgrounds around the world.
The Science Behind it
Humans have approximately 19,000–20,000 genes. When genes are passed from parents to their children, small changes called mutations can occur in the DNA. Most of these changes are harmless, but some can affect how the body grows and functions.
PC is caused by a mutation in one of five keratin genes. Keratin proteins help make skin, nails, and other tissues strong. When one of these genes has a mutation, it can lead to the skin and nail problems associated with PC.
The signs and symptoms of PC can vary from person to person, depending on which keratin gene is affected and the specific mutation that is present.
Who gets it?
Anyone can have PC. Because it is caused by a genetic mutation, any baby can be born with PC, although the chances are very low. When PC occurs in someone with no family history of the condition, it is called a spontaneous mutation. This is not caused by anything a parent did or did not do—it simply happens by chance.
However, the chance of having PC is much higher if one of your parents has the condition. In this case, there is a 50% chance with each pregnancy that the baby will inherit PC. This is why, if one parent has PC, one child may have it while another sibling may not.
Why is it called PC?
The term Pachyonychia Congenita means “thick nails.” Pachy means thick, and onychia refers to nails. While many people with PC have thickened nails, others may have only one thickened toenail while the rest of their nails appear normal. The term PC is used to describe mutations in one of five keratin genes that affect the skin and can lead to one or more of the symptoms described below.
What it may look like
Because PC can be caused by mutations in one of five closely related keratin genes, its signs and symptoms can vary greatly from person to person. Some people have thickened nails on their hands and/or feet. Others develop thick areas of skin called calluses on their feet, and sometimes on their hands. Some people develop cysts, which can appear as small or large bumps on or under the skin. Many people have a combination of these symptoms.
Here are some examples of the different ways PC can appear.
Is PC Contagious?
No! PC is a genetic condition, which means it cannot be caught from someone else. Individuals are born with PC; they either have the condition or they do not. PC is also not contagious, meaning it cannot be spread to others.
How is it different from thick skin that lots of people have?
People with PC may have been told they “just have thick skin,” similar to the kind many people develop as they get older. While both types of thick skin are caused by a buildup of dead skin cells, the underlying cause is very different. Because of this, thick skin caused by PC can be extremely painful and make walking difficult, while thick skin in people without PC is often painless.
Is there a cure?
Unfortunately, not yet. Currently, treatments are available to help manage the symptoms of PC, such as thickened skin and nails. However, there is not yet a way to prevent PC from occurring or stop it from developing.
Many researchers around the world are working to better understand PC, what causes it, and how it may one day be treated in ways that could prevent or reduce its symptoms. This important work is ongoing at research centers around the world.
