Diagnosis of Wilson's Disease: A Comprehensive Review

Abstract

Wilson's disease is an autosomal recessive disorder of copper metabolism. The culprit gene is ATP7B. The worldwide prevalence is about 1 in 30,000, which may vary by population. Higher prevalence rates were reported using more sensitive screening techniques and pilot population screening. Typical presentations include neuropsychiatric and hepatic dysfunction, whereas atypical presentations are protean. Diagnosis relies on a high clinical suspicion, typical neurological symptoms, presence of Kayser-Fleischer rings, and reduced serum ceruloplasmin concentration. The conventional value of < 0.20 g/l is not a universal diagnostic value. Age of the subjects and analytical variations should be considered when interpreting these levels. Patients with inconclusive findings require further investigations such as 24 h urinary free-copper excretion, penicillamine challenge test, liver copper measurement, and detection of gene mutations. Direct molecular diagnosis remains the most decisive tool. Other tests such as non-ceruloplasmin–bound copper are unreliable. Potential pitfalls and limitations of these diagnostic markers are critically reviewed in this paper. The mainstays of therapy are trientine, penicillamine, and/or zinc. Liver transplantation is lifesaving for those with advanced disease. Ceruloplasmin oxidase activity and serum free-copper concentration should be monitored in patients on long-term de-coppering therapy to prevent iatrogenic copper deficiency.

Key words :

• ATP7B gene
• ceruloplasmin
• ceruloplasmin oxidase activity
• copper
• Ferenci score
• hepatic copper quantitation
• mutation analysis
• non–ceruloplasmin–bound copper
• penicillamine challenge test
• population screening
• receiver operating characteristic curve analysis
• sensitivity and specificity
• serum free copper
• trafficking
• Wilson's disease

Abbreviations
BI-PASA,	=	bidirectional PCR amplification;
CI,	=	confidence interval;
COMMDI 1,	=	a protein that is deleted in Bedlington terriers with copper toxicosis;
ELISA,	=	enzyme-linked immunosorbent assay;
KF,	=	Kayser-Fleischer;
NCBI,	=	National Center for Biotechnology Information;
PCR,	=	polymerase chain reaction;
ROC,	=	receiver-operator characteristic;
SNP,	=	single-nucleotide polymorphism;
WD,	=	Wilson's disease.

Abbreviations
BI-PASA,	=	bidirectional PCR amplification;
CI,	=	confidence interval;
COMMDI 1,	=	a protein that is deleted in Bedlington terriers with copper toxicosis;
ELISA,	=	enzyme-linked immunosorbent assay;
KF,	=	Kayser-Fleischer;
NCBI,	=	National Center for Biotechnology Information;
PCR,	=	polymerase chain reaction;
ROC,	=	receiver-operator characteristic;
SNP,	=	single-nucleotide polymorphism;
WD,	=	Wilson's disease.