Familial juvenile idiopathic arthritis in three siblings including dichorionic diamniotic twins: a case series highlighting familial aggregation and genetic susceptibility

Abstract

Juvenile idiopathic arthritis (JIA) is the most common chronic rheumatologic disorder of childhood and is considered a multifactorial disease with genetic and environmental contributions. Familial occurrence of JIA remains relatively uncommon and clinically significant. We report a case series involving three siblings born out of a non-consanguineous marriage, including dichorionic diamniotic twin male siblings, presenting with inflammatory arthritis suggestive of oligoarticular juvenile idiopathic arthritis with recurrent episodes, separated by symptom-free intervals. The elder sibling, an eleven-year-old female, presented with recurrent fever and associated inflammatory arthritis involving the right wrist and elbow. The twin siblings presented with recurrent knee and wrist arthritis, elevated inflammatory markers and ultrasonographic evidence of synovitis. Both the twins had episodes previously diagnosed as reactive arthritis before evolving into a probable JIA phenotype. Extensive investigations excluded infectious, cardiac and other connective tissue etiologies. All siblings demonstrated favorable response to non-steroidal anti-inflammatory therapy. This case series highlights possible familial aggregation, genetic susceptibility and phenotypic variability in JIA.