Pachyonychia congenita (PC) is a rare genetic disorder that affects the development of skin, hair, and nails of the hand and feet. It is caused by mutations in one of several genes, including KRT6A, KRT6B, KRT6C, KRT16, or KRT17, which provide instructions for making proteins that are important for the structural integrity of these tissues.
The most prominent feature of pachyonychia congenita is thickened nails (pachyonychia), which can be discolored, ridged, and prone to infections. Other common symptoms include painful calluses on the soles of the feet and palms of the hands (hyperkeratosis), blisters and sores in the mouth, and cysts on the skin.
There are two types of pachyonychia congenita: the more severe Jadassohn-Lewandowsky type, which is present at birth or early infancy, and the milder Jackson-Lawler type, which develops later in childhood or adolescence.
Pachyonychia congenita is a lifelong condition that currently has no cure. Treatment is focused on managing symptoms, such as reducing pain and preventing infections, and may include topical or oral medications, surgery, or physical therapy. There are new treatments being looked into. Genetic counseling is also recommended for affected individuals and their families.