Peculiarities of PAPA syndrome

To describe a family from New Zealand with the pyogenic arthritis, pyoderma gangrenosum and acne (PAPA) syndrome, an autoinflammatory, variably expressed, erosive destructive form of arthritis.

Information was gained through medical records and interviews of the affected patients and wider family. DNA sequencing was performed at Seay Center for Musculoskeletal Research Texas Scottish Rite Hospital for Children.

Five patients were affected over three generations with an E250Q mutation found on the CD2BP1 gene on chromosome 15. Common features included a severe, pauciarticular-onset, destructive peripheral arthritis, beginning at ages 5, 5, 2, 3 and 1(1/2) years. This combination marked cervical ankylosis (in two members), micrognathia and a more severe phenotype is unique. A third-generation family member treated early with DMARDs is following a less severe course. The skin involvement was variable, all with degrees of acne from puberty, though only one patient displayed pyoderma gangrenosum. A clear pattern of the arthritis switching off in adolescence and the triggering of skin disease was observed.

Differing degrees of joint destruction, and cervical ankylosis in this family with the E250Q mutation demonstrate PAPA syndrome's variable expression. Further understanding of this rare condition and its pathway may allow better targeting of treatments, not just for families with this specific syndrome but also for other, more common, forms of arthritis.