Wilson disease

Wilson disease is an inherited disorder in which excessive amounts of copper accumulate in the body, particularly in the liver, brain, and eyes. Typically, signs and symptoms of Wilson disease first appear between the ages of 6 and 40, but most often begin during the teenage years.

Liver disease is usually the initial feature of Wilson disease in people between the ages of 6 and 45. Signs and symptoms of liver disease include yellowing of the skin or the whites of the eye (jaundice), fatigue, loss of appetite, and abdominal swelling. Psychiatric or nervous system problems commonly occur in young adults with Wilson disease. Signs and symptoms of these problems can include clumsiness, trembling, difficulty walking, speech problems, deteriorating school work, depression, anxiety, and mood swings. In many individuals with Wilson disease, copper deposits form a green-to-brownish ring, called the Kayser-Fleischer ring, around the cornea (the front surface of the eye). Abnormalities in eye movements, such as the restricted ability to gaze upwards, may also occur.

Wilson disease is a rare disorder that affects approximately 1 in 30,000 individuals.

Mutations in the ATP7B gene cause Wilson disease.

Normal variations in the PRNP gene modify the course of Wilson disease.

The ATP7B gene provides instructions for making a protein that plays a role in the transport of copper from the liver to other parts of the body. This protein is particularly important for the elimination of excess copper from the body. Mutations in the ATP7B gene prevent the transport protein from functioning properly. With a shortage of functional protein, excess copper is not removed from the body. As a result, copper accumulates to toxic levels that can damage tissues and organs, particularly the liver and brain.

A normal variation in the PRNP gene may delay the age of onset of Wilson disease and affect the type of symptoms that develop. The PRNP gene provides instructions for making prion protein, which is active in the brain and other tissues. This protein also appears to be involved in transporting copper. Studies have focused on the effects of a PRNP gene variation that affects position 129 of the prion protein. At this position, the protein building block (amino acid) methionine or valine is used. Among people who have mutations in the ATP7B gene, it appears that the onset of symptoms of Wilson disease is delayed by several years if they have methionine (instead of valine) at position 129 in the prion protein. Research findings also suggest that methionine, instead of valine, at position 129 may be associated with an increased occurrence of symptoms that affect the nervous system, particularly tremors. Larger studies are needed, however, before the effects of this PRNP variation on Wilson disease can be established.

Read more about the ATP7B and PRNP genes.

This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.