What is Wilson disease?
Wilson disease is a genetic disorder that prevents the body from getting rid
of extra copper. People who get Wilson disease inherit two abnormal copies of the ATP7B gene, one from each parent. Wilson
disease carriers, who have only one copy of the abnormal gene, do not have symptoms. Most people with Wilson disease have
no known family history of the disease. A person’s chances of having Wilson disease increase if one or both parents
have it. Wilson disease is caused by a buildup of copper in the body. Normally, copper from the diet
is filtered out by the liver and released into bile, which flows out of the body through the gastrointestinal tract. People
who have Wilson disease cannot release copper from the liver at a normal rate, due to a mutation of the ATP7B gene. When the
copper storage capacity of the liver is exceeded, copper is released into the bloodstream and travels to other organs—including
the brain, kidneys, and eyes. A small amount of copper obtained from food is needed to stay healthy,
but too much copper can cause symptoms
About one in 40,000 people get Wilson disease.
It equally affects men and women. Symptoms usually appear between ages 5 to 35, but new cases have been reported in people
aged 2 to 72 years.
A buildup of copper in the liver may cause ongoing liver disease. Rarely, acute liver failure
occurs; most patients develop signs and symptoms that accompany chronic liver disease, including...
• Swelling
of the liver or spleen
• Jaundice, or yellowing of the skin and whites of the eyes
• Fluid
buildup in the legs or abdomen
• A tendency to bruise easily
• Fatigue
A buildup of copper in the central nervous system may result in neurologic symptoms, including...
• Problems with speech, swallowing, or physical coordination
• Tremors or uncontrolled movements
• Mmuscle stiffness
• Behavioral changes
Other signs and symptoms of Wilson disease include...
• Anemia
• Low platelet
or white blood cell count
• Slower blood clotting, measured by a blood test
• High levels
of amino acids, protein, uric acid, and carbohydrates in urine
• Premature osteoporosis and arthritis
During the physical examination, a doctor will look for visible signs of Wilson disease. A special light called a slit lamp
is used to look for Kayser-Fleischer rings in the eyes. Kayser-Fleischer rings are present in almost all people with Wilson
disease who show signs of neurologic damage but are present in only 50 percent of those with signs of liver damage alone.
Laboratory tests measure the amount of copper in the blood, urine, and liver tissue. Most people with Wilson disease will have a lower than normal level of copper in the blood and
a lower level of corresponding ceruloplasmin, a protein that carries copper in the bloodstream. In cases of acute liver
failure caused by Wilson disease, the level of blood copper is often higher than normal. A 24-hour urine collection will show
increased copper in the urine in most patients who display symptoms.
Genetic testing may help diagnose Wilson disease in some people, particularly those with a family history of the disease.
Wilson disease can be misdiagnosed because it is rare and its symptoms are similar to those of other conditions.
Anyone with unexplained liver disease or neurologic symptoms with evidence of liver disease, such as abnormal liver
tests and symptoms of liver disease, should be screened for Wilson disease. People with a family history of Wilson disease,
especially those with an affected sibling or parent, should also be screened. A doctor can diagnose Wilson disease before
the appearance of symptoms. Early treatment can reduce or even prevent illness.
Initial therapy includes the removal
of excess copper, a reduction of copper intake, and the treatment of any liver or central nervous system damage.
Most doctors prescribe the drugs d-penicillamine (Cuprimine) and trientine hydrochloride (Syprine), which release copper
from organs into the bloodstream. Most of the copper is then filtered out by the kidneys and excreted in urine. A potential
major side effect of both drugs is that neurologic symptoms can become worse—a possible result of the newly released
copper becoming reabsorbed by the central nervous system. About 20 to 30 percent of patients using d-penicillamine will also
initially experience other reactions to the medication, including fever, rash, and other drug-related effects on the kidneys
and bone marrow.
Pregnant women should be made aware that d-penicillamine
or trientine hydrochloride taken during pregnancy increases the risk of birth defects.
Zinc, administered as zinc salts such as zinc acetate (Galzin), blocks the digestive tract’s absorption of
copper from food. Zinc removes copper more slowly and safely. Maintenance therapy begins when symptoms improve and tests
show that copper has been reduced to a safe level.
People with
Wilson disease should reduce their dietary copper intake. They should not eat shellfish or liver, as these foods may contain
high levels of copper. Other foods high in copper—including mushrooms, nuts, and chocolate—should be avoided during
initial therapy but, in most cases, may be eaten in moderation during maintenance therapy. People with Wilson disease should
have their drinking water checked for copper content and should not take multivitamins that contain copper.
If
the disorder is detected early and treated effectively, people with Wilson disease can enjoy good health.
Points
to Remember...
Wilson disease prevents the body from getting rid of extra copper.
Wilson disease first attacks
the liver, the central nervous system, or both.
Anyone with unexplained liver disease or neurologic symptoms with evidence
of liver disease should be screened for Wilson disease.
If the disorder is detected early and treated effectively, people
with Wilson disease can enjoy good health.