Camptodactyly-Arthropathy-Coxa Vara-Pericarditis Syndrome Resembling Juvenile Idiopathic Arthritis: A Single-Center Experience from Southern Turkey

An adult with cystathionine beta-synthase deficiency, camptodactyly-arthropathy-coxa vara-pericarditis syndrome, and deafness: A case report

Massive sequencing platforms allow the identification of complex clinical phenotypes involving more than one autosomal recessive disorder. In this study, we report on an adult patient, born to a related couple (third degree cousins), referred for genetic evaluation due to ectopia lentis, deafness and previous diagnosis of juvenile idiopathic arthritis. He was biochemically diagnosed as having Classic Homocystinuria (HCU); Sanger sequencing of the CBS gene showed the genotype NM_000071.2(CBS):c.[833T>C];[833T>C], compatible with the diagnosis of pyridoxine-responsive HCU. As he also had symptoms not usually associated with HCU, exome sequencing was performed. In addition to the variants found in the Sanger sequencing, the following variants were identified: NM_001256317.1(TMPRSS3):c.[413C>A];[413C>A]; and the NM_005807.6(PRG4):c.[3756dup]:[3756dup], confirming the diagnosis of autosomal recessive nonsyndromic deafness and Camptodactyly-Arthropathy-Coxa Vara-Pericarditis Syndrome (CACP), respectively. Genomic analysis allowed the refinement of the diagnosis of a complex case and improvement of the patient's treatment.

Thirteen Indians with camptodactyly-arthropathy-coxa vara-pericarditis syndrome

Camptodactyly-arthropathy-coxa vara-pericarditis (CACP) syndrome (MIM# 208250) is a rare monogenic disorder, characterized by early onset of camptodactyly, progressive coxa vara, bilateral arthropathy and constrictive pericarditis. The syndrome is caused by biallelic loss-of-function variants in PRG4. Deficiency of PRG4 results in progressive worsening of joint deformity with age. Thirteen individuals with CACP syndrome from eight consanguineous Indian families were evaluated. We used exome sequencing to elucidate disease-causing variants in all the probands. These variants were further validated and segregated by Sanger sequencing, confirming the diagnosis of CACP syndrome in them. Seven females and six males aged 2-23 years were studied. Camptodactyly (13/13), coxa vara (11/13), short femoral neck (11/13) and arthritis in large joints (12/13) [wrists (11/13), ankle (11/13), elbow (10/13) and knee (10/13)] were observed commonly. Five novel disease-causing variants (c.3636G>T, c.1935del, c.1134dup, c.1699del and c.962T>A) and two previously reported variants (c.1910_1911del and c.2816_2817del) were identified in homozygous state in PRG4. We describe the phenotype and mutations in one of the large cohorts of patients with CACP syndrome, from India.

A novel mutation in the proteoglycan 4 gene causing CACP syndrome: two sisters report

BACKGROUND

Camptodactyly-arthropathy-coxa vara-pericarditis (CACP) syndrome, caused by biallelic pathogenic mutations in the proteoglycan 4 (PRG4) gene, is characterized by early-onset camptodactyly, noninflammatory arthropathy, coxa vara deformity, and rarely, pericardial effusion. This syndrome can mimic juvenile idiopathic arthritis. CACP syndrome is caused by mutations in the proteoglycan 4 (PRG4) gene. To date, only 36 pathogenic mutations have been reported in this gene, but none have been reported from Azerbaijan.

CASE PRESENTATION

Herein, we report two siblings presented with chronic polyarthritis, had a prior diagnosis of juvenile idiopathic arthritis, but was subsequently diagnosed as CACP syndrome with novel mutation in the PRG4 gene.

CONCLUSION

Our report expands the knowledge of PRG4 mutations, which will aid in CACP patient counseling.

A Diagnosis of Camptodactyly With Benign Joint Hypermobility Syndrome in a Patient Presenting With Fixed Flexion Deformity of the Fingers and Striae

Camptodactyly is a genetic disorder that causes fixed flexion deformity of one or more fingers of single or both hands. It is very rare and the occurrence is very low amongst the children. It is linked to a handful of congenital connective tissue syndromes. It is passed onto generations with reduced expressivity. However, its association with benign joint hypermobility syndrome is rarely known. Joint hypermobility syndrome is a condition where there is extreme joint flexibility and it is related to a set of articular and extra-articular sequelae. We herein report a case of camptodactyly with benign joint hypermobility syndrome in a patient presenting with fixed flexion deformity of the fingers, joint hyperextensibility, and striae.

Pseudo-rheumatic manifestations of limping: Camptodactyly-arthropathy-coxa vara-pericarditis syndrome: Single case report and review of the literature

Camptodactyly-arthropathy-coxa vara-pericarditis (CACP) syndrome is a rare genetic disease characterized by tetrad camptodactyly, noninflammatory arthropathy, coxa vara deformity, and pericardial effusion. Arthropathy typically affects large joints and presents with joint swelling in the absence of other signs of inflammation. We described the case of a girl affected by CACP syndrome caused by a novel compound heterozygous variant in proteoglycan 4 gene (c.2831_2832insT; c.3892C > T) and associated with temporomandibular involvement. The patient received treatment with intra-articular hyaluronic acid injections, which presented rapid but transient improvements of pain and range of motion. A literature review of previously reported CACP patients has been performed. Of the patients. 69.2% (101 out of 146) were Middle Eastern, and 65.7% (96) were consanguineous. The median age of onset was 24 months (interquartile range of 12-36 months), and median age of diagnosis was 96 months (interquartile range of 48-156 months). Arthropathy was always present, mainly involving hips (95.2%), knees (92.4%), wrists (87.7%), elbows (79.5%), and ankles (57.5%). Camptodactyly and pericardial effusion were described, respectively, in 97.3% (142) and 15.1% (22) of patients. The main radiological findings were coxa vara (95.2%), femoral changes (64.4%), intraosseus cysts (14.4%), and bone erosion (5%). Of the patients, 32.9% (48) had received a previous juvenile idiopathic arthritis diagnosis. CACP syndrome can be easily misdiagnosed with juvenile idiopathic arthritis. A prolonged lack of response to immunosuppressive therapy associated with typical clinical and radiological features should prompt consideration of this rare syndrome.