• Wilson's disease
• liver
• fulminant hepatic failure

The paper by Gow et al (Gut 2000;46:415–19) discussed the diagnosis of Wilson's disease in 30 patients presenting to two different clinical facilities over 28 years (1971–1998). Because a paper of this type is likely to be viewed as an authoritative guide, it is important that the information be valid. For that reason, I call attention to the following significant errors in the paper.

The authors report urine copper values of 5, 4, 7, 4, 5, 2, and 2 μg per 24 hours in seven patients in their table 1. These data cannot possibly be valid. The normal range for urine copper is 20–50 μg per 24 hours, and these patients are far below the lower limit of normal. In performing several thousand 24 hour urine copper tests on patients and normal subjects in our own laboratory, I have never seen one below 10 μg per 24 hours, except in copper deficiency. The patients in table 1 have Wilson's disease, the opposite of copper deficiency, making the data even more unbelievable. I …