Wilson disease is a hereditary disease in which excessive amounts of copper accumulate in the body. The disease affects approximately one in every 30,000 Canadians. Small amounts of copper are essential to good health, but the inability of the body, and especially the liver, to release excessive amounts results in accumulation of copper in several organs. This overload of copper has a toxic effect on these organs. The liver is the main organ to store copper and when its storage capacity is exhausted, copper accumulates in the brain and the cornea of the eye. Left untreated, Wilson disease can be fatal.
What causes the disease?
Wilson disease is hereditary. In order to have the disease, a person must have inherited two defective genes, one from each parent; each brother or sister of a patient has a 25 per cent chance of being affected. The liver begins to retain copper at birth and it may take years before symptoms manifest themselves.
What are the symptoms of Wilson disease?
Wilson disease is sometimes difficult to diagnose. Patients may have no symptoms for years. When symptoms develop, they can be subtle. Sometimes symptoms of Wilson disease resemble hepatitis. Alternatively, some patients have an enlarged liver and spleen and liver test abnormalities. Copper accumulation in the brain can present itself in two ways:
Individuals between 3 and 45 years of age who show signs of any of the previously mentioned symptoms should be screened for Wilson disease. Any child or teenager with unexplained liver disease should be tested for Wilson disease. The diagnosis can be confirmed with blood tests measuring serum copper and ceruloplasmin, a blood protein that contains copper. Another diagnostic test for this disease is the presence of Kayser-Fleischer rings which show an accumulation of copper around the cornea, sometimes visible to the naked eye, but usually requiring slit-lamp examination. Measurements of urinary copper are also useful for making the diagnosis.
The gene responsible for Wilson disease has been discovered. Conclusive genetic testing is now available to diagnose affected brothers and sisters before they show disease symptoms. Individuals who are found to have the defective gene can be treated before problems arise. Now that the gene responsible for Wilson disease has been identified, more research is needed to identify all of the changes in the gene.
How is the disease treated?
Once detected, effective treatments are available to treat Wilson disease, even in advanced stages. The toxic concentration of copper in the body must be removed and its reaccumulation prevented. This is done with the use of a decoppering agent such as penicillamine or with high-dose zinc.
Can it be completely cured?
The treatment does not correct the fundamental flaw in liver function. Therefore, to prevent reaccumulation of copper in the body, treatment must be continued throughout the patient's entire lifetime.
What precautions should be taken against this disease?
Since the gene transmitting the disease is recessively inherited, siblings of a patient have a 25 per cent chance of being affected. Therefore, when a new case is diagnosed, all siblings should be screened for the disease.
What else can we learn about it?
The Canadian Liver Foundation is proud to have supported research that helped in the discovery of the Wilson disease gene. Now that the defective gene has been identified, more research is needed to identify all of the changes in the gene.
The Canadian Liver Foundation raises funds for research into liver diseases such as Wilson disease. Our mandate is to reduce the incidence and impact of all liver diseases. Research will provide a much better understanding of the disease and could make a cure available in the future. This is a rapidly changing field of medicine; information in this publication is current for June 2005.
If you would like more information on Wilson disease or any other liver disease, please contact us.