Wilson's disease is an autosomal recessive genetic disorder of copper metabolism caused by mutations in the ATP7B gene on chromosome 13q14.3[1]. The disease leads to progressive copper accumulation in the liver, brain, basal ganglia, and cornea, resulting in hepatic cirrhosis, neuropsychiatric symptoms, and characteristic Kayser-Fleischer rings. With early diagnosis and lifelong treatment, most patients have a normal life expectancy[@cauenburg2017].
The ATP7B gene encodes a P-type copper-transporting ATPase (ATP7B protein) expressed primarily in hepatocytes. ATP7B has two primary functions:
More than 600 disease-causing mutations have been identified in ATP7B, including missense, nonsense, splice-site, insertion, and deletion variants. The H1069Q mutation (histidine at position 1069 replaced by glutamine) accounts for 50-70% of cases in Northern European and North American populations. Other common mutations include R778L (common in East Asian populations) and del2874 (common in Southern European populations)[1:1].
The pathophysiology of copper accumulation follows a staged progression:
Free copper acts as a potent catalyst in oxidative stress reactions, generating reactive oxygen species (ROS) through the Haber-Weiss reaction:
The resulting hydroxyl radicals (OH•) cause lipid peroxidation, protein oxidation, DNA damage, and mitochondrial dysfunction. Key targets include:
Wilson's disease typically presents between ages 5 and 40, with two major clinical phenotypes:
Liver disease in Wilson's disease ranges from asymptomatic elevation of transaminases to fulminant hepatic failure:
Neurological symptoms typically develop after age 15 and reflect copper deposition in the basal ganglia, particularly the putamen and globus pallidus:
Movement Disorders:
Neuropsychiatric Features:
Neurological Examination Findings:
| Feature | Score |
|---|---|
| Kayser-Fleischer rings | 2 |
| Neuropsychiatric symptoms | 2 |
| Serum ceruloplasmin < 0.1 g/L | 1 |
| Coombs-negative hemolysis with high serum copper | 1 |
| 24-hour urinary copper > 1.6 μmol (100 μg) | 2 |
| Quantitative liver copper > 4 μmol/g (250 μg/g) | 2 |
| Mutation analysis (2 pathogenic alleles) | 4 |
A score of 4 or more confirms diagnosis. A score of 2-3 requires additional testing.
Treatment aims to remove accumulated copper and prevent further accumulation. Lifelong therapy is mandatory.
Chelating Agents:
| Drug | Mechanism | Dose | Side Effects |
|---|---|---|---|
| Penicillamine | Copper chelation, increases urinary excretion | 750-1500 mg/day (250 mg qid) | Pyridoxine deficiency, neurological worsening (20-50%), rash, bone marrow suppression, nephrotic syndrome[7] |
| Trientine | Copper chelation, less pyridoxine interference | 750-1500 mg/day (250 mg tid) | Similar to penicillamine but fewer neurological side effects[7:1] |
Metallothionein Inducers:
Indications include:
Liver transplantation corrects the metabolic defect as ATP7B is expressed in hepatocytes, and outcomes are excellent with >85% 10-year survival.
Research is exploring gene therapy approaches to deliver functional ATP7B to hepatocytes, including AAV vectors and CRISPR-Cas9 editing of patient hepatocytes ex vivo followed by autologous transplantation. These approaches remain experimental but hold promise for permanent correction[2:1].
| Feature | Wilson's Disease | Parkinson's Disease | Huntington's Disease |
|---|---|---|---|
| Gene | ATP7B | SNCA, LRRK2, PARKIN, PINK1, GBA | HTT (CAG repeat) |
| Protein defect | Copper transport ATPase | Alpha-synuclein aggregation | Mutant huntingtin |
| Primary site | Liver, basal ganglia | Substantia nigra | Striatum (caudate, putamen) |
| Movement disorder | Dystonia, parkinsonism | Bradykinesia, rigidity, tremor | Chorea, dystonia |
| Kayser-Fleischer rings | Present in neurological cases | Absent | Absent |
| Liver involvement | Primary and early | Not typical | Not typical |
| Inheritance | Autosomal recessive | Mostly autosomal dominant | Autosomal dominant |
With early diagnosis and consistent treatment:
Neurological worsening occurs in 20-50% of patients within the first 1-3 months of chelation therapy, thought to be due to mobilization of copper from the liver to the brain. This is not a reason to stop treatment and often resolves with continued therapy[3:1].
Bull PC, Thomas GR, Rommens JM, et al. The Wilson disease gene is a putative copper-transporting P-type ATPase similar to the Menkes gene. Nature Genetics. 1993. ↩︎ ↩︎
Ferenci P, Czlonkowski A. Wilson Disease. GeneReviews. 2020. ↩︎ ↩︎
Lorincz MT. Neurologic Wilson's disease. Annals of the New York Academy of Sciences. 2010. ↩︎ ↩︎
Schilsky ML, Stockert RJ, Sternlieb I. Liver transplantation in Wilson disease. A pediatric perspective. Journal of Pediatric Gastroenterology and Nutrition. 1999. ↩︎ ↩︎
Litwin T, Gromadzka G, Czlonkowski A, et al. Movement disorders in Wilson disease: a prospective study of 100 patients. Journal of the Neurological Sciences. 2015. ↩︎
Kim JH, Kim Y, Kim B, et al. Brain structural changes and neuropsychiatric manifestations in Wilson disease: a cross-sectional study. Neurology. 2019. ↩︎
Weiss KH, Thurik F, Gotthardt DN, et al. Efficacy and safety of oral chelators in treatment of patients with Wilson disease. Clinical Gastroenterology and Hepatology. 2013. ↩︎ ↩︎