The gold standard for diagnosis of Wilson’s disease is:
(a) Demonstration of Kayser-Fleischer rings
(b) Urinary copper excretion
(c) Serum ceruloplasmin
(d) Liver biopsy with quantitative copper assays
ANS- (d) Liver biopsy with quantitative copper assays
Serum ceruloplasmin levels should not be used for definitive diagnosis, because they are normal in up to 10% of affected patients and are reduced in 20% of carriers.
Kayser-Fleischer rings can be definitively diagnosed only by an ophthalmologist using a slit lamp. They are present in >99% of patients with neurologic/psychiatric forms of the disease and have been described very rarely in the
absence of Wilson’s disease. Kayser-Fleischer rings are present in only ∼30–50% of patients diagnosed in the hepatic or presymptomatic state; thus, the absence of rings does not exclude the diagnosis.
About half of presymptomatic patients who are ultimately affected have diagnostically elevated urine copper values, but the other half have levels that are in an intermediate range between 0.9 and 1.6 μmol (60–100 μg) per 24 h.
The gold standard for diagnosis remains liver biopsy with quantitative copper assays. Affected patients have values >3.1 μmol/g (>200 μg/g [dry weight] of liver).