bart–pumphrey syndrome bart–pumphrey syndrome bart–pumphrey syndrome (also known as "palmoplantar keratoderma with knuckle pads and leukonychia and deafness") is a cutaneous condition characterized by hyperkeratoses (knuckle pads) over the metacarpophalangeal, proximal and distal interphalangeal joints. bart–pumphrey syndromespecialtydermatology it was characterized in 1967. it can be associated with gjb2.