Copper Deficiency in Wilson's Disease with a Normal Zinc Value.

Copper deficiency (CD) is a rare complication of long-term treatment of Wilson's disease (WD) and is usually accompanied by high serum zinc levels. A 57-year-old woman with WD presented with limb weakness and sensory disturbance due to myeloneuropathy and macrocytic anemia after 36 years of treatment. Markedly reduced serum free copper values confirmed CD, which was considered to be caused by progressive dysphagia and severe diarrhea rather than zinc overdose because of the normal serum zinc levels. Discontinuing copper-reducing therapy and increasing copper intake improved her symptoms. Physicians should be alert for the risk of CD in WD patients, especially those with dysphagia.