Wilson's disease presenting with arthralgia: a case report.

Backgrounds: Wilson's disease (WD) is a rare autosomal recessive disorder of copper metabolism characterized by impaired hepatic copper excretion and progressive multisystem copper accumulation. While hepatic and neuropsychiatric manifestations predominate, arthralgia as an initial presentation is uncommon. We report a child with WD who presented initially with joint pain. Case presentation: A ten-year-old patient experienced recurrent joint pain, predominantly in the lower limbs, and physical examination revealed tenderness in the right ankle joint and hepatomegaly. Laboratory investigations demonstrated liver dysfunction, including elevated alanine aminotransferase, aspartate aminotransferase, and total bilirubin levels. Further evaluation confirmed the diagnosis of WD based on the presence of Kayser-Fleischer rings on ophthalmologic examination, decreased serum ceruloplasmin levels, increased 24-hour urinary copper excretion, and identification of a homozygous mutation in the ATP7B gene. Treatment with penicillamine and zinc supplementation was initiated, after which the child experienced gradual improvement in joint symptoms along with normalization of liver biochemical parameters. Conclusion: WD should be considered in the differential diagnosis of children presenting with unexplained arthralgia, particularly when accompanied by abnormal liver biochemical findings.