Peculiarities of PAPA syndrome

Area of Science:

• Genetics and molecular biology
• Rheumatology and immunology
• Dermatology

Background:

• Pyogenic arthritis, pyoderma gangrenosum, and acne (PAPA) syndrome is a rare autoinflammatory disorder characterized by recurrent fevers, sterile joint inflammation, and skin manifestations.
• Genetic mutations, particularly in the CD2BP1 gene, have been implicated in the pathogenesis of PAPA syndrome, leading to dysregulation of inflammatory pathways.

Observation:

• A multi-generational family in New Zealand presented with clinical features consistent with PAPA syndrome.
• Genetic analysis revealed a novel E250Q mutation in the CD2BP1 gene in affected family members, confirming the diagnosis.
• Phenotypic variability was observed, with differing degrees of joint destruction, skin involvement, and the presence of unique features like cervical ankylosis and micrognathia.

Findings:

• The E250Q mutation in the CD2BP1 gene segregates with PAPA syndrome in this family, demonstrating its causative role.
• Early treatment with disease-modifying antirheumatic drugs (DMARDs) in a third-generation patient suggested a potentially milder disease course.
• A distinct pattern of arthritis onset in childhood followed by adolescent remission and subsequent skin disease manifestation was noted.

Implications:

• This study highlights the variable clinical expression of PAPA syndrome, even within the same family, underscoring the importance of genetic testing for accurate diagnosis.
• Understanding the molecular mechanisms underlying PAPA syndrome may offer insights into the pathogenesis of other autoinflammatory and destructive arthritic conditions.
• Targeted therapeutic strategies, informed by genetic and molecular insights, could improve treatment outcomes for patients with PAPA syndrome and related inflammatory disorders.