Wilson disease results in accumulation of copper in the liver and other organs. Hepatic or neurologic symptoms develop. Diagnosis is based on a low serum ceruloplasmin level, high urinary excretion of copper, and sometimes liver biopsy results. Treatment consists of a low-copper
(See also Overview of Mineral Deficiency and Toxicity.)
Wilson disease is a disorder of copper metabolism that affects men and women; about 1 person in 30,000 has the disorder. Affected people are homozygous for the mutant recessive gene, located on chromosome 13. Heterozygous carriers, who constitute about 1.1% of the population, are asymptomatic.
Pathophysiology of Wilson Disease
The genetic defect in Wilson disease impairs copper transport. The impaired transport decreases copper secretion into the bile, thus causing the copper overload and resultant accumulation in the liver, which begins at birth. The impaired transport also interferes with incorporation of copper into the copper protein ceruloplasmin, thus decreasing serum levels of ceruloplasmin.
Hepatic fibrosis develops, ultimately causing cirrhosis. Copper diffuses out of the liver into the blood, then into other tissues. It is most destructive to the brain but also damages the kidneys and reproductive organs and causes hemolytic anemia. Some copper is deposited around the rim of the cornea and edge of the iris, causing Kayser-Fleischer rings. The rings appear to encircle the iris.
Symptoms and Signs of Wilson Disease
Symptoms of Wilson disease usually develop between ages 5 and 35 but can develop from age 2 to 72 years.
In almost half of patients, particularly adolescents, the first symptom is
Hepatitis—acute, chronic active, or fulminant
But hepatitis may develop at any time.
In about 40% of patients, particularly young adults, the first symptoms reflect
Central nervous system (CNS) involvement
Motor deficits are common, including any combination of tremors, dystonia, dysarthria, dysphagia, chorea, drooling, and incoordination. Sometimes the CNS symptoms are cognitive or psychiatric abnormalities.
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In 5 to 10% of patients, the first symptom is incidentally noted gold or greenish gold Kayser-Fleischer rings or crescents (due to copper deposits in the cornea), amenorrhea or repeated miscarriages, or hematuria.
Diagnosis of Wilson Disease
Slit-lamp examination for Kayser-Fleischer rings
Serum ceruloplasmin, sometimes serum copper, and 24-hour urinary copper excretion
Wilson disease should be suspected in people < 40 with any of the following:
An unexplained hepatic, neurologic, or psychiatric disorder
An unexplained persistent elevation in hepatic transaminases
A sibling, parent, or cousin with Wilson disease
Fulminant hepatitis
If Wilson disease is suspected, slit-lamp examination for Kayser-Fleischer rings is required, and serum ceruloplasmin levels and 24-hour urinary copper excretion are measured. Serum copper levels may be measured, but ceruloplasmin levels are usually sufficient. Transaminase levels are also often measured; high levels are consistent with the diagnosis.
Kayser-Fleischer rings
These rings plus typical motor neurologic abnormalities or a decrease in ceruloplasmin are nearly pathognomonic for Wilson disease. Rarely, these rings occur in other liver disorders (eg, biliary atresia, primary biliary cirrhosis), but ceruloplasmin levels should be unaffected.
Ceruloplasmin
Serum ceruloplasmin (normally 20 to 35 mg/dL [200 to 350 mg/L]) is usually low in Wilson disease but can be normal. It can also be low in heterozygous carriers and those with other liver disorders (eg, viral hepatitis, drug- or alcohol-induced liver disease). A low ceruloplasmin level in a patient with a Kayser-Fleischer ring is diagnostic. Also, a level of < 5 mg/dL (< 50 mg/L) is highly suggestive regardless of clinical findings.
Serum copper
Serum copper levels are sometimes measured; however, they may be high, normal, or low.
Urinary copper excretion
In Wilson disease, 24-hour urinary copper excretion (normally, ≤ 30 mcg/day) is usually > 100 mcg/day. If serum ceruloplasmin is low and urinary copper excretion is high, diagnosis is clear. If levels are equivocal, measuring urinary copper
Liver biopsy
In unclear cases (eg, elevated transaminases, no Kayser-Fleischer rings, indeterminate values for ceruloplasmin and urinary copper), the diagnosis is made by doing a liver biopsy to measure hepatic copper concentration. However, false-negative results may occur because of a sampling error (due to large variations in copper concentrations in the liver) or fulminant hepatitis (causing necrosis that releases large amounts of copper).
Screening for Wilson disease
Because early treatment is most effective, screening is indicated for anyone who has a sibling, cousin, or parent with Wilson disease. Screening consists of a slit-lamp examination and measurement of transaminase levels, serum copper and ceruloplasmin, and 24-hour urine copper excretion. If any results are abnormal, liver biopsy is done to measure hepatic copper concentration.
Infants should not be tested until after age 1 year because ceruloplasmin levels are low during the first few months of life. Children < 6 years with normal test results should be retested 5 to 10 years later.
Genetic testing is under investigation.
Treatment of Wilson Disease
Low-copper diet
Continual, lifelong treatment of Wilson disease is mandatory regardless of whether symptoms are present. A low-coppercopper from accumulating. Copper content in drinking water should be checked, and people should be advised not to take any vitamin or mineral supplements containing copper.
Zinc acetate)
Poor long-term adherence to drug therapy is common. After 1 to 5 years of therapy, lower dose maintenance drug therapy can be considered. Regular follow-up care with an expert in liver disease is recommended.
Liver transplantation may be lifesaving for patients who have Wilson disease and fulminant hepatic failure or severe hepatic insufficiency refractory to drugs.
Prognosis for Wilson Disease
Prognosis for patients with Wilson disease is usually good, unless disease is advanced before treatment begins.
Untreated Wilson disease is fatal, usually by age 30.
Key Points
Wilson disease is a rare, autosomal recessive disorder in which copper accumulates in various organs.
The disease manifests during childhood or adulthood, usually between ages 5 and 35.
Suspect the disorder in people with a family history of the disorder or unexplained hepatic, neurologic, or psychiatric abnormalities (including elevated transaminase levels).
Confirm the diagnosis primarily with a slit-lamp examination (for Kayser-Fleischer rings) and measurement of serum ceruloplasmin (which is low) and 24-hour urinary copper excretion (which is high).
Advise patients to follow a low copper
