Wilson’s disease

Wilson's disease is a rare inherited disorder of copper metabolism. In a healthy body, copper an essential trace mineral obtained from food is absorbed in the small intestine, transported to the liver, used where needed, and excreted into bile, which carries it out of the body through the digestive tract. This elegant system keeps copper levels within a safe range.

In Wilson's disease, that excretion mechanism is broken. A mutation in the ATP7B gene which encodes a copper-transporting protein in liver cells means the liver cannot properly incorporate copper into ceruloplasmin (a copper-carrying protein in the blood) or excrete it into bile. Copper that cannot be excreted has nowhere to go. It accumulates first in the liver, then, as the liver's storage capacity is exceeded, it spills into the bloodstream and deposits in other organs: the brain, the eyes, the kidneys, and the heart.

The accumulation is gradual, which is why Wilson's disease typically does not produce symptoms in early childhood. Most people develop their first symptoms between the ages of 5 and 35, though cases have been reported in patients as young as 2 and as old as 70. The pattern of organ involvement varies considerably between individuals some present primarily with liver disease, others with neurological or psychiatric symptoms, and some with a combination.

Wilson's disease affects approximately 1 in 30,000 people worldwide, making it rare but not vanishingly so. It is autosomal recessive meaning a person must inherit one defective copy of the ATP7B gene from each parent to develop the disease. Carriers people with one defective copy do not develop Wilson's disease themselves but can pass the mutation to their children.

The symptoms of Wilson's disease are remarkably variable, which is one reason the condition is frequently misdiagnosed — sometimes for years. The presentation depends on where copper is accumulating most aggressively and how far the disease has progressed.

Liver symptoms are the most common presentation in children and young adults. Copper accumulation in the liver causes hepatitis-like inflammation, which may present as fatigue, nausea, loss of appetite, abdominal discomfort in the upper right quadrant, and jaundice. Some patients are identified incidentally when routine blood tests show elevated liver enzymes. Others present with more advanced disease — cirrhosis, portal hypertension, or acute liver failure.

Acute liver failure in Wilson's disease is a particularly dramatic presentation that can occur in adolescents and young adults, sometimes as the very first sign of the disease. It is characterised by rapidly developing jaundice, coagulopathy, kidney failure, and haemolytic anaemia — a combination that is considered virtually pathognomonic for Wilson's disease and that constitutes a medical emergency requiring immediate specialist assessment.

Neurological symptoms develop when copper deposits in the basal ganglia and other regions of the brain. They typically emerge in the second to fourth decade of life and include tremor — often a characteristic "wing-beating" tremor of the outstretched arms — dysarthria (slurred speech), dysphagia (difficulty swallowing), dystonia (involuntary muscle contractions causing abnormal postures), and problems with coordination and gait. Some patients develop a mask-like facial expression, drooling, or significant difficulties with handwriting.

Psychiatric symptoms are among the most commonly missed manifestations of Wilson's disease and are responsible for many of the diagnostic delays that occur. Personality changes, mood disturbances, anxiety, depression, impulsive behaviour, and psychosis have all been described. Young people presenting with new-onset psychiatric symptoms — particularly in combination with any liver abnormalities — should have Wilson's disease excluded.

Kayser-Fleischer rings are copper deposits in the periphery of the cornea, visible as golden-brown rings at the outer edge of the iris. They are present in virtually all patients with neurological Wilson's disease and in the majority of those with liver disease. They are detected by slit-lamp examination performed by an ophthalmologist — they cannot be reliably seen with the naked eye. Their presence is one of the most specific signs of Wilson's disease.

Renal involvement occurs in some patients, causing problems with kidney tubular function — the kidneys leak amino acids, glucose, phosphate, and uric acid, a pattern called Fanconi syndrome.

Haematological manifestations include Coombs-negative haemolytic anaemia — destruction of red blood cells driven by copper toxicity — which can accompany liver disease and acute presentations.

Other less common features include joint pain, osteoporosis, cardiac arrhythmias, and skin changes.

Wilson's disease is caused exclusively by mutations in the ATP7B gene, located on chromosome 13. This gene provides the instructions for making a copper-transporting ATPase — a protein embedded in the membrane of liver cells that is responsible for moving excess copper into bile for excretion.

Over 900 different mutations in the ATP7B gene have been identified, and most patients are compound heterozygotes — meaning they carry two different mutations, one on each copy of chromosome 13. The specific mutation influences, to some degree, the severity and pattern of disease, though genotype-phenotype correlations in Wilson's disease are imprecise, and even siblings with the same mutations can present very differently.

For a child to develop Wilson's disease, both parents must carry at least one defective ATP7B gene. Each child of two carrier parents has a 25 percent chance of inheriting both defective copies and developing the disease, a 50 percent chance of being a carrier, and a 25 percent chance of inheriting two normal copies.

The defective ATP7B protein fails to perform its copper-transporting function adequately. Initially, the liver compensates by storing excess copper in specialised proteins — but storage capacity is finite. Once exceeded, copper leaks into the bloodstream and deposits throughout the body, causing progressive oxidative damage to cells in every organ it reaches.

Diagnosing Wilson's disease requires a combination of tests — no single test is both sensitive and specific enough to confirm or exclude the diagnosis on its own. This is one reason diagnosis is sometimes delayed.

Serum ceruloplasmin is typically the first test ordered. Ceruloplasmin — the copper-carrying protein produced by the liver — is low in approximately 80 to 85 percent of patients with Wilson's disease. However, it can be normal in some patients, particularly those with acute liver failure, and it can be low in other conditions — so a low ceruloplasmin alone is not diagnostic.

Serum copper is often paradoxically low in Wilson's disease because most circulating copper is bound to ceruloplasmin, and ceruloplasmin levels are reduced. However, free (non-ceruloplasmin-bound) copper — which is the toxic fraction — is elevated and can be calculated from total copper and ceruloplasmin values.

24-hour urine copper is one of the most useful diagnostic tests. Urinary copper excretion is elevated in Wilson's disease — typically above 100 micrograms per 24 hours (normal is below 40). In patients with neurological Wilson's disease, values are often dramatically elevated. This test is also used to monitor the adequacy of Wilson's disease treatment — copper excretion in urine provides a direct measure of how effectively the body is being de-coppered.

Slit-lamp examination for Kayser-Fleischer rings is performed by an ophthalmologist. Their presence in a patient with liver or neurological disease is highly suggestive of Wilson's disease. Their absence does not exclude it — rings may be absent in patients presenting purely with liver disease.

Liver biopsy with hepatic copper quantification is the gold standard investigation. A small tissue sample is taken from the liver and the copper content measured directly. Hepatic copper above 250 micrograms per gram dry weight is characteristic of Wilson's disease. Biopsy also assesses the degree of fibrosis and inflammation.

Genetic testing for ATP7B mutations is increasingly available and is particularly useful for family screening — testing siblings and children of diagnosed patients to identify those who have inherited the disease before symptoms develop.

The Leipzig score is a validated diagnostic scoring system that combines multiple findings — ceruloplasmin level, Kayser-Fleischer rings, neurological symptoms, liver copper, urine copper, and genetic findings — into a total score that guides diagnosis. A score of four or more points confirms Wilson's disease.

Wilson's disease treatment is lifelong and highly effective when started early and maintained consistently. The goals are to remove excess copper already accumulated in the body and to prevent further copper accumulation — protecting the liver, brain, and other organs from ongoing damage.

There are four main therapeutic approaches, used either alone or in combination depending on the patient's presentation, disease phase, and individual circumstances.

D-Penicillamine

D-penicillamine was the first effective treatment of Wilson disease and has been used for over 60 years. It is a copper chelator — a drug that binds copper in the body and dramatically increases its excretion in the urine. It is highly effective at removing copper and reversing liver and neurological damage in many patients.

However, d-penicillamine comes with a significant side effect profile. Up to 30 percent of patients experience adverse reactions — including skin rashes, fever, kidney problems (proteinuria), bone marrow suppression, and autoimmune reactions. A particularly important concern is neurological worsening in patients who present with neurological symptoms: paradoxically, initiating d-penicillamine in neurologically affected patients can cause a dramatic deterioration — the neurological paradoxical reaction — thought to occur as copper is mobilised from the liver and redistributes to the brain before being fully excreted. This paradoxical worsening occurs in up to 50 percent of neurologically presenting patients started on d-penicillamine and can be irreversible — making drug choice critical in this group.

Trientine (Triethylene Tetramine)

Trientine is an alternative copper chelator that is increasingly used as first-line therapy — particularly in patients who cannot tolerate d-penicillamine or who present with neurological disease. It has a significantly better tolerability profile than d-penicillamine and a lower risk of the neurological paradoxical reaction. Many specialists now prefer trientine as the first-line chelating agent, particularly for newly diagnosed patients.

Trientine works through a similar mechanism to d-penicillamine — binding copper in the gut and tissues and facilitating its urinary excretion — but its binding chemistry differs, which accounts for its different side effect profile.

Zinc Salts

Zinc — given as zinc acetate, zinc sulphate, or zinc gluconate — works through an entirely different mechanism from the chelators. Rather than binding and removing copper from the body, zinc blocks copper absorption in the intestine. It does this by inducing metallothionein — a protein in intestinal cells that binds copper with very high affinity, trapping it in intestinal cells that are then shed naturally.

Zinc is not powerful enough to be used as the sole initial treatment of Wilson disease in symptomatic patients — it works too slowly to address the urgent copper burden in someone with active liver or neurological disease. However, it is excellent as maintenance therapy once the copper burden has been reduced by chelation. It has a very favourable safety profile and is the preferred maintenance agent in many patients, including pregnant women with Wilson's disease.

Tetrathiomolybdate (TM)

Ammonium tetrathiomolybdate is a newer copper chelator with a very low risk of neurological paradoxical reaction — making it particularly attractive for patients presenting with neurological symptoms. It forms a stable complex with copper and albumin in the blood, rendering copper non-toxic and preventing its uptake by tissues. While not yet universally approved, it is available at specialist centres in several countries and is showing considerable promise in clinical trials.

Symptomatic and Supportive Treatment

Beyond copper-targeted therapy, management includes treating the consequences of copper accumulation — antiviral or hepatoprotective measures for liver disease, neurological rehabilitation for patients with movement disorders, and psychiatric support for those with behavioural or mood disturbances.

Monitoring Treatment

Regular monitoring is central to effective Wilson's disease treatment. Every six to twelve months, patients should have serum copper and ceruloplasmin measured, 24-hour urinary copper quantified, liver function tests performed, and neurological status assessed. The aim is to keep free serum copper below 15 micrograms per decilitre and to achieve urinary copper levels in a target range that reflects adequate — but not excessive — copper removal.

Dietary copper restriction is a useful adjunct to medical Wilson's disease treatment though it is important to understand that diet alone cannot manage Wilson's disease and should never replace medication.

Foods to avoid or limit:

• Shellfish — particularly oysters, mussels, clams, and lobster contain extremely high concentrations of copper and should be avoided entirely.
• Organ meats — especially liver and kidney are among the richest dietary sources of copper and should be excluded from the diet.
• Nuts and seeds — including cashews, sunflower seeds, and almonds contain moderate to high copper and should be limited, particularly in the early treatment phase.
• Chocolate and cocoa products contain significant copper and should be consumed only in small amounts or avoided.
• Mushrooms — particularly dried mushrooms are relatively high in copper and warrant restriction.
• Whole grain products contain more copper than refined grains. While refined grains are not nutritionally ideal, during active treatment phases, moderating whole grain intake is reasonable.

Regarding water: Copper plumbing can leach copper into drinking water, particularly in older homes. Running the tap for a minute before drinking, using filtered water, or drinking bottled water reduces this exposure. In households with older copper piping, testing the water copper content is advisable.

What to eat: A generally healthy, balanced diet emphasising vegetables, fruits, fish (non-shellfish), poultry, eggs, and dairy provides adequate nutrition without excessive copper loading. Working with a registered dietitian who has knowledge of metabolic liver disease is worthwhile, particularly in the early months of treatment.

While the treatments for Wilson's disease are effective and generally well tolerated when properly monitored, they carry specific complication risks that require vigilance.

D-Penicillamine complications are the most numerous. Early hypersensitivity reactions — fever, rash, and lymphadenopathy — occur within the first weeks of treatment in some patients and require drug withdrawal. Nephrotoxicity — protein in the urine indicating kidney involvement — can develop with long-term use and requires dose reduction or switching. Bone marrow suppression causing low blood counts is a serious but less common complication requiring regular full blood count monitoring. Autoimmune syndromes — including drug-induced lupus and myasthenia gravis — are rare but recognised adverse effects. The neurological paradoxical worsening on initiating d-penicillamine in neurologically presenting patients remains the most clinically significant and feared complication.

Trientine complications are less common and generally milder — iron deficiency anaemia (because trientine can also chelate iron), and rare cases of bone marrow suppression. Gastrointestinal intolerance occurs in a minority of patients.

Zinc complications are minimal at therapeutic doses. Mild gastric irritation is the most common complaint, usually manageable by taking zinc with a small amount of food. Very high doses can suppress copper too aggressively, causing copper deficiency — a condition with its own neurological consequences — which is why monitoring remains important even on zinc maintenance therapy.

Over-treatment — excessive copper removal — can cause copper deficiency, which paradoxically produces neurological symptoms similar to those of Wilson's disease itself, including peripheral neuropathy, myelopathy, and anemia. Regular monitoring of copper status prevents this.

Treatment interruption — stopping medication without medical guidance — is perhaps the most dangerous complication of all. Wilson's disease is a lifelong condition. Stopping treatment, even temporarily, can trigger acute liver failure. There are documented cases of patients who felt well, assumed they were cured, stopped their medication, and developed life-threatening liver failure within months. The medication is not treating symptoms — it is managing a permanent metabolic defect.

Wilson's disease is one of the most treatable serious inherited metabolic disorders. When diagnosed early and treated consistently, patients can expect a normal life expectancy. Liver disease often stabilizes or improves, with liver function tests normalizing and liver fibrosis regressing in many cases. Neurological symptoms such as tremor and movement difficulties also improve in most patients, although recovery may take 12–24 months and some residual deficits can remain if diagnosis is delayed.

For patients who develop severe liver failure or end-stage cirrhosis, liver transplantation is life-saving and permanently corrects the underlying metabolic defect. Family screening of first-degree relatives is crucial because early, pre-symptomatic diagnosis allows treatment before organ damage occurs. The key to excellent outcomes is simple: diagnose early, treat continuously, monitor regularly, and never stop treatment without medical supervision. With these measures, most patients live full, healthy lives.