Familial arthropathy in Saudi Arabian children: demographic, clinical, and biochemical features.

BACKGROUND

Familial arthropathy comprises a heterogeneous group of arthropathies. It can be either an inflammatory or a noninflammatory condition. The worldwide frequency of these disorders is unknown.

OBJECTIVE

To study the demographic, clinical and biochemical features, and survival of a large series of children with familial arthropathies.

METHODS

The medical records of children who had an arthropathy and a family history of a similar condition at the Pediatric Rheumatology Clinic at King Faisal Specialist Hospital-Riyadh between 1990 and 2005 were reviewed. These included children with familial juvenile idiopathic arthritis (FJIA), infantile systemic hyalinosis (ISH), the nodulosis-arthropathy-osteolysis (NAO) syndrome, and the camptodactyly-arthropathy-coxa vara (CAC) syndrome. Familial rheumatic diseases including spondyloarthropathies or known syndromes associated with articular manifestations were excluded. In each case age, gender, presenting symptoms, laboratory data, diagnostic procedures, and provisional and final diagnoses as well as treatment and outcome were reviewed.

RESULTS

Sixty-two children with various familial arthropathies were reviewed. Twelve children (9 female/3 male) with FJIA presented with polyarthritis. These children belonged to 4 unrelated families, all of whom were from the same geographical area, with 2 families belonging to the same tribe. The mean age at onset was 2.4 years, and mean age at diagnosis was 3.5 years. All children had high inflammatory markers. Nineteen children (11 male/8 female) with ISH presented in the neonatal period with painful joint contractures and typical mucocutaneous features. The referral diagnosis was inaccurate in 14 patients. Thirteen patients were the product of first-degree cousin marriages, and 5 families had more than 1 affected child. Radiological findings included periosteal reaction and osteolytic lesions. Tissue biopsy was performed in 8 patients and the findings were consistent with the diagnosis in all 8 patients. Despite aggressive management, 16 patients died. The mean age of the remaining 3 surviving children was 20 months. There were 15 children (9 female/6 male) with the NAO syndrome with a mean age at onset of 3.4 years. They were from 7 unrelated families; 5 families had more than 1 affected child. The referral diagnosis was juvenile idiopathic arthritis (JIA). Most children presented with painful deformed hands. Eleven children (70%) had advanced osteolytic changes. All children had normal inflammatory markers. There were 16 children (11 male/5 female) with the CAC syndrome who were diagnosed at a mean age of 3.7 years. Camptodactyly presented at birth or in first months of life, while other features developed in early childhood. JIA was the referral diagnosis. Fourteen children had bilateral coxa vara. Two children exhibited symptoms or signs of pericarditis. Inflammatory markers were normal in all children.

CONCLUSIONS

Familial arthropathies are not uncommon conditions which may be easily confused with JIA, causing a delay in diagnosis and management. Careful evaluation of a child presenting with an arthropathy, particularly in a population where consanguinity is common, is required for timely and accurate diagnosis. Overall, the prognosis of these conditions remains guarded despite treatment.