How is Wilson disease diagnosed?
Wilson disease results from excessive copper accumulation in association with ceruloplasmin deficiency. The capacity of hepatocytes to store copper is exceeded, and excessive free copper is deposited in the liver and at extrahepatic sites such as the brain and kidney, where it attacks cell membranes and DNA because of its redox properties. Decreased serum ceruloplasmin (<200 mg/L) and elevated urinary copper excretion (>65–100 μg/day) are suggestive of Wilson disease. An elevated hepatic copper concentration (>250 μg Cu/g dry weight) is the most reliable test early in the course of the illness. Screening of first-degree relatives older than 6 years should include a physical examination, liver function tests, measurement of serum copper, ceruloplasmin, and 24-hour urine copper, and slit lamp examination. Siblings of patients with Wilson disease have a 25% risk of having the disease and children of patients have a 1 in 200 risk.
