Wilson disease

Wilson disease is a genetic disorder marked by the accumulation of toxic levels of copper in many tissues and organs, primarily in the brain, liver, kidneys, and the cornea of the eyes.

Wilson disease is classified as a chronic liver disease because it causes a progressive destruction of the liver for more than 6 months.

It is a genetic disease due to mutations in the gene ATP7B, located on chromosome 13 (13q14.3), which is involved in the copper transport activity.

It is inherited with an autosomal recessive pattern (it is necessary to inherit two changed genes, one from each parent).

Wilson disease affects approximately 1 in 40,000 individuals with both sexes affected equally.

Symptoms usually appear between 4 and 40 years of age.

The main symptoms related to Wilson disease are:

• Dystonia: Uncontrolled muscle movements in extremities, shoulders, arms, hands, legs.
• Dysarthria: Difficulty speaking (unintelligible speech).
• Dysphagia: Swallowing difficulties, inability to swallow saliva and drooling.
• Increased anger, and inappropriate behavior.
• Ataxia (uncoordinated movements that cause difficulty with walking and balance).

The symptoms above become stronger during menstruation, or when suffering fever, depression or stress.

A typical sign of Wilson disease is a brownish or greenish pigmentation around the iris of the eyes, called Kayser-Fleischer rings, due to deposition of copper in the cornea.

Diagnosis can be made by clinical symptoms plus laboratory values consistent with Wilson disease:

• Low levels of ceruloplasmin in the blood
• Liver biopsy that shows an increase in hepatic copper content
• Increased urinary excretion of copper

The recommended treatment of Wilson disease is a combination of drugs to decrease the amount of copper in the body and a low copper diet.

The following drugs are usually used:

• D-penicillamine to remove tissue copper. It may have a number of serious side effects and it usually reduces the number of platelets in the blood.
• Trientine (trientine hydrochloride) a copper-chelating agent, which leads to enhanced urinary copper excretion.
• Zinc-based therapy (zinc acetate) or ammonium tetrathiomolybdate to prevent copper absorption in the gut.

It is also encouraged to follow a diet low in copper. Foods to be avoided for the high levels of copper include:

• Cereals: Oats, rye and wheat.
• Vegetables: Artichokes, potatoes, broccoli and mushrooms.
• Legumes: Chickpeas, lentils, beans, peas.
• Nuts: Walnuts, almonds, hazelnuts, pistachios.
• Meat: Organ meats, liver, kidneys.
• Fish: Herring, salmon, cod.
• Chocolate.
• Shellfish: Oysters.