Progressive pseudorheumatoid dysplasia involving a novel WISP3 mutation and sacroiliac and hip arthritis: A case report and literature review.

Introduction: Progressive pseudorheumatoid dysplasia (PPRD) is a rare autosomal recessive genetic disease caused by mutations in the Wnt1-inducible signaling pathway protein 3 gene. PPRD is considered a noninflammatory disease, and involvement of the sacroiliac joint and hip arthritis have not been reported previously.

Patient Concerns: We report a case of PPRD in an 11-year-old boy, who presented with bilateral pain and swelling in the knees, elbows, and ankles, and bilateral pain without swelling in the shoulders, wrists, knuckles, and proximal and distal interphalangeal joints for the past 5 years. He had been misdiagnosed with juvenile idiopathic arthritis for more than 6 years.

Diagnosis: The correct PPRD diagnosis was made using whole-exome sequencing for Wnt1-inducible signaling pathway protein 3 gene mutations (c.589 + 2T>C and c.721T>G; both mutations have rarely been reported) and magnetic resonance imaging examination; moreover, the latter showed inflammation of the sacroiliac joint and hip joint.

Intervention: The patient was administered supplemental calcium, active vitamin D, and glucosamine sulfate.

Outcome: The patient experienced alleviation of joint pain following treatment initiation; however, joint motion improvement was not obvious. Above all, the long-term use of biologic or targeted synthetic disease-modifying antirheumatic drugs in the future was avoided.

Conclusion: The findings of the inflammatory aspects in PPRD will enrich our understanding of this rheumatological disease.