Mutations in 18 Canadian Families With Punctate Palmoplantar Keratoderma and a Possible Link to Cancer.

Background: Punctate palmoplantar keratoderma type 1 (PPPK1) presents in late childhood to adulthood with multiple small discrete hyperkeratotic papules on palms and soles. PPPK1 is an autosomal dominant skin disease caused by mutations. It has been suggested that PPPK1 may be associated with an increased predisposition to systemic malignancies.