Delayed-onset progressive pseudorheumatoid dysplasia with secondary synovial chondromatosis.

A 25-year-old man presented to us with progressive multiple joint pain, enlargement, and restricted movements. X-rays showed platyspondyly, multiple epiphyseal widening, synovial chondromatosis, and decreased bone stock and cortical thickness. Genetic testing showed biallelic pathogenic variants in CCN6 which confirmed the diagnosis of progressive pseudorheumatoid dysplasia. Supportive care, physical therapy, genetic and psychological counselling were provided to the patient.