Which are the causes of Pachyonychia Congenita?

TL;DR: Pachyonychia congenita is caused by pathogenic mutations in one of five specific keratin genes that provide structural integrity to skin and nail cells. These genetic errors disrupt the formation of keratin filaments, leading to the characteristic thickening of nails, painful palmoplantar keratoderma, and other epithelial issues.

What causes Pachyonychia Congenita at the genetic level?

Pachyonychia congenita is a rare autosomal dominant genetic disorder. It is caused by mutations in genes that encode keratins, the "scaffolding" proteins that give skin, hair, and nails their strength. When these genes are mutated, the resulting keratin proteins are structurally unstable, causing cells to collapse under the mechanical stress of walking or gripping, which leads to the painful blistering and thickening seen in Pachyonychia Congenita.

Which genes are involved in Pachyonychia Congenita?

The molecular basis of Pachyonychia Congenita involves five specific genes. Mutations in these genes disrupt the keratin intermediate filament network:

• KRT6A and KRT6B


• KRT6C


• KRT16


• KRT17

Are there environmental triggers for Pachyonychia Congenita?

While the root cause of Pachyonychia Congenita is strictly genetic, environmental factors can significantly influence the severity of symptoms. Mechanical trauma—such as friction from walking or ill-fitting footwear—is a major trigger for the painful plantar keratoderma and blistering that many of our 4 Pachyonychia Congenita community members experience. Managing these mechanical stressors is a core component of clinical care.

Is the etiology of Pachyonychia Congenita fully understood?

While we understand the specific genes responsible for Pachyonychia Congenita, researchers are still investigating why the same mutation can manifest with varying severity between individuals. Current research is focused on "molecular therapies," such as small interfering RNA (siRNA) and rapamycin, which aim to silence the mutant gene or mitigate the cellular stress caused by Pachyonychia Congenita.

Next steps

• Consult with a dermatologist or a geneticist to confirm your diagnosis through genetic testing.


• Join the Pachyonychia Congenita community at DiseaseMaps.org to connect with others who share your experience.


• Review clinical trial updates via the Pachyonychia Congenita Project (PC Project).

Medical disclaimer: This content is for informational purposes only and does not constitute professional medical advice, diagnosis, or treatment; always seek the advice of your physician.

References

• Orphanet: Pachyonychia congenita (ORPHA:676)


• NIH GARD: Pachyonychia congenita


• OMIM: Pachyonychia congenita (Entry #167200)


• Pachyonychia Congenita Project (PC Project)