G08: Sciences Genetic Disorders: Pachyonychia Congentia

achyonychia congenita (PC) is a rare keratinizing skin disorder inherited in an autosomal dominant fashion. The predominant characteristics are severe plantar pain, palmoplantar keratoderma (PPK) including calluses with underlying blisters and variable hypertrophic nail dystrophy, often accompanied by oral leukokeratosis, cysts of various types, follicular hyperkeratosis, palmoplantar hyperhidrosis and sometimes natal teeth.

Pachyonychia congenita (PC) is a very rare genetic disorder that affects the skin and nails. The symptoms usually begin at birth or early in life, and the condition affects people of both sexes and all racial and ethnic groups.

PC is caused by mutations affecting keratins, proteins that provide structural support to cells, and it is classified into five types based on which keratin gene harbors the mutation. Symptoms vary from person to person and depend on the type, but thickened nails and calluses on the soles of the feet occur in almost all cases. The most debilitating symptom is painful calluses on the soles that make walking difficult. Some patients rely on a cane, crutches, or a wheelchair to help manage the pain of walking.