- Indian Rheumatology association
Dogga Prasanna Kumar MD, DM
Consultant Immunology & Rheumatology, KIMS Hospitals, Vizag, Andhra Pradesh
Case 1: Case Presentation
A 16-year-old female referred to our Rheumatology clinic with a history of right wrist pain and swelling for 5 months and polyarthralgia which was being treated as Juvenile Idiopathic arthritis with only mild improvement on NSAIDs and DMARDs (Methotrexate). On examination she had multiple bony tender points on the dorsum of right hand with bony tenderness in the right wrist and right forearm bones. Routine investigations revealed normal Complete blood count, inflammatory markers (ESR and CRP) with low calcium and vitamin D levels, normal phosphorus and alkaline phosphatase levels. X ray showed osteoma-like lesions with endosteal thickening of the first, second metacarpal, carpal bones, lower end of the radius, humerus around elbow (Figure 1A,1B). Bone scan showed increased tracer uptake in distal 1/3 rd of right radius, few carpal bones of right wrist (scaphoid/lunate/trapezoid), 1st and 2nd metacarpal bones and phalanges of right 2nd and 3rd digits, around elbow joint extending into lower 1/3rd of humerus (Figure 1C).
Melorheostosis
Melorheostosis is a condition of unusual mesenchymal dysplasia which frequently occurs in late adolescence with equal prevalence in both sexes typically affecting the appendicular skeleton in a limited segmental fashion (1). It must be differentiated from similar bone conditions presenting with increased bone density (osteopetrosis, osteosclerosis and hyperostosis) and conditions with ectopic ossification on radiology. However, asymmetrical, and restricted involvement of the medial or lateral side of the affected bones contrasts with the often-generalized nature of other conditions with increased bone density (2). In view of rarity of the disease and pathogenetic mechanisms involving increased numbers of osteoclast and osteoblasts with marked increased remodeling of bone favours the use of Bisphosphonates and Surgical management in case of compressive symptoms (3)
Suggested Reading
Case 2: Case Presentation
A 21-Year-old male symptomatic since 6 years of age presented to Rheumatology OPD with chief complaints of progressive deformities of both small and large joints. His illness started when he started noticing mild flexion deformity at the small joints of both hands (PIP and DIP) with mild restriction of movements. Over the next 2 years he started to notice similar complaints of restriction of movements at the large joints at elbow with progressive deformities of small joints of hands. .Further he started to notice flexion deformities at the lower limb joints involving knee and ankle. The deformities were progressive and were painless causing restriction of movements with difficulty in daily household activities. For the last 5 years he started to notice mechanical back pain with progressive kyphosis.
Family history of the same type of deformities in his two elder siblings (elder brother and sister). On examination he had fixed and non-correctable deformities of small joints of hands involving PIP, DIP, bilateral wrist (Figure A), elbows, shoulder, knees and ankles with kyphotic posture. Interphalangeal joints showed a knobby appearance and there was no evidence of synovitis. Investigations showed normal inflammatory markers with low calcium and Vitamin D. Radiographs of both hands (Figure B) [showing reduced joint space between carpal bones and at PIP,DIP joints] and dorsal lumbar spine showing flattening and anterior beaking of vertebrae [platyspondyly] (lateral view- Figure C).
What is the likely diagnosis and the most common gene mutation associated?
Progressive Pseudo rheumatoid Dysplasia (PPRD)
Most common gene associated is WISP3 gene
Progressive pseudo rheumatoid dysplasia (PPRD) is a skeletal dysplasia characterized by predominant involvement of articular cartilage with progressive joint stiffness and enlargement in the absence of inflammation. Onset – typically between ages three and six years – begins with the involvement of the interphalangeal joints. Over time, involvement of large joints and the spine causes significant joint contractures, gait disturbance, and scoliosis and/or kyphosis, resulting in abnormal posture and significant morbidity. Despite considerable arthropathy, pain is not a major presenting feature of this condition. Initially height is normal; however, short stature (<3rd centile) becomes evident in adolescence as the skeletal changes progress. The diagnosis of PPD is established in a proband with characteristic radiographic features and/or identification of biallelic pathogenic
variants in CCN6 (formerly WISP3) on molecular genetic testing. Treatment is supportive.
Suggested Reading
Bhavani GS, Shah H, Shukla A, Dalal A, Girisha KM. Progressive Pseudorheumatoid Dysplasia. 2015 Nov 25 [updated 2020 Dec 23]. In: Adam MP, Feldman J, Mirzaa GM, Pagon RA, Wallace SE, Amemiya A, editors. Seattle (WA): University of Washington, Seattle; 1993–2025. PMID: 26610319.
