Wilson’s disease
Wilson’s disease
Introduction
Wilson’s disease is a rare autosomal recessive genetic disorder characterised by defective copper metabolism, leading to the accumulation of copper in various tissues — primarily the liver, brain, eyes (corneas), and kidneys. Without treatment, this copper overload causes progressive damage to multiple organ systems.
Peak Incidence
- Most commonly presents between 10 and 25 years of age.
Pathophysiology
- Caused by mutations in the ATP7B gene, leading to impaired copper transport and reduced incorporation of copper into caeruloplasmin.
- Copper accumulates first in the liver and then disseminates to other organs, causing hepatic, neurological, and psychiatric manifestations.
- Excess free copper can also cause intravascular haemolysis and renal tubular dysfunction.
Symptoms
Hepatic Symptoms
- Chronic hepatitis (present in ~40% of cases).
- Cirrhosis (may develop over time).
- Ascites and splenomegaly (due to portal hypertension).
- Acute liver failure in severe cases.
Neurological Symptoms (~50% of cases)
- Parkinsonism: tremor, bradykinesia, rigidity.
- Dysarthria (slurred or difficult speech).
- Dystonia (abnormal muscle tone and posturing).
- Chorea (involuntary jerky movements).
- Cognitive decline and dementia.
- Motor symptoms may be asymmetrical.
Psychiatric Symptoms (~10% of cases)
- Depression.
- Mood disturbances and irritability.
- Personality changes and, in some cases, psychosis.
Signs
Hepatic
- Hepatomegaly.
- Jaundice.
- Ascites.
- Splenomegaly.
Neurological
- Tremor.
- Rigidity and bradykinesia.
- Dystonia.
- Asterixis (flapping tremor).
- Ataxia.
- Cognitive impairment.
Psychiatric
- Features such as depression, personality change, or psychosis.
Other
- Kayser-Fleischer rings – green-brown copper deposits at the corneal margins (seen on slit-lamp examination).
- Haemolytic anaemia – due to free copper-induced red cell destruction.
- Renal tubular dysfunction – may lead to Fanconi syndrome.
- Osteoporosis and pathological fractures.
Diagnosis
Copper Studies (Mainstay of Diagnosis)
- Low serum caeruloplasmin – a copper-binding protein that is usually reduced in Wilson’s disease.
- 24-hour urinary copper excretion – elevated levels support the diagnosis.
- Low total serum copper but increased free (non-caeruloplasmin-bound) copper.
Blood Tests
- FBC – may show haemolytic anaemia:
- Low haptoglobin.
- Elevated reticulocyte count.
- Raised unconjugated bilirubin.
- Liver function tests (LFTs):
- Mixed hepatocellular-cholestatic picture.
- AST/ALT raised (often higher than ALP).
- GGT may be elevated.
- ALP may appear disproportionately low in acute liver failure.
Additional Investigations
- Genetic testing – confirms mutations in the ATP7B gene (gold standard for definitive diagnosis).
- Liver biopsy – may show hepatic copper accumulation (>250 µg/g dry weight).
- MRI brain – may reveal basal ganglia changes. The “face of the giant panda” sign is a rare but characteristic finding.
- Slit-lamp examination – to identify Kayser-Fleischer rings.
- Coombs test – negative in haemolytic anaemia caused by Wilson’s (non-immune).
- Blood film – may show spherocytes or schistocytes.
Complications
- Cirrhosis and decompensated liver failure.
- Hepatocellular carcinoma (rare but possible).
- Irreversible neurological deterioration.
- Psychiatric morbidity and reduced quality of life.
- Haemolytic anaemia.
- Renal impairment.
- Osteoporosis and fractures.
Management
Copper Chelation Therapy
- Penicillamine – first-line chelating agent (monitor for adverse effects).
- Trientine hydrochloride – alternative chelator, used if penicillamine is not tolerated.
Zinc Therapy
- Zinc salts – inhibit intestinal copper absorption and are used for maintenance therapy after copper depletion.
Dietary Modifications
- Avoid high-copper foods: shellfish, liver, nuts, chocolate, mushrooms, and copper-containing supplements.
Liver Transplantation
- Considered in acute liver failure or decompensated cirrhosis unresponsive to medical therapy.
Symptomatic Management
- Neurological: Physical therapy, speech therapy, and medications for tremor or dystonia.
- Psychiatric: Antidepressants, mood stabilisers, or antipsychotics as appropriate.
- Occupational therapy to support daily living.
Monitoring
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Regular monitoring of:
- Liver function tests.
- 24-hour urinary copper excretion.
- Serum free copper.
- Neurological and psychiatric status.
FAQ from our users
What is the genetic inheritance of Wilson’s disease?
- Autosomal recessive.
- Caused by mutations in the ATP7B gene on chromosome 13.
- The gene is responsible for removing excess copper from the body via bile excretion.
- Without this, copper builds up in the body.
Why can Wilson’s cause Parkinson-like symptoms?
- Copper deposits accumulate in the basal ganglia, particularly in the putamen and globus pallidus, leading to motor dysfunction.
What is serum caeruloplasmin?
- A copper-transporting protein in the blood.
- Low levels suggest Wilson’s disease but can be falsely normal or elevated in certain conditions (e.g., cancer, chronic inflammation).
Common pitfalls in a clinical setting
Common pitfalls in a clinical setting
- Wilson’s disease can present with vague symptoms like psychiatric changes, mild tremor, or liver dysfunction.
- Consider Wilson’s disease in patients with unexplained liver or neurological symptoms between 10–25 years.