[Genetic disorders of copper transport--diagnosis and new treatment for the patients of Wilson's disease].

Wilson's disease and Menkes disease are inherited genetic disorders of copper metabolism. Each disease results from the absence or dysfunction of homologous copper-transporting ATPases present in the trans-Golgi network of cells. The Wilson ATPase transports copper into the hepatocyte secretory pathway for incorporation into ceruloplasmin and excretion into the bile. Thus, patients with Wilson's disease of the autosomal recessive trait present with signs and symptoms arising from impaired biliary copper excretion. The Menkes ATPase transports copper across the placenta, gastrointestinal tract, and blood-brain barrier, and the clinical features of this X-linked disease arise from copper deficiency. Despite striking differences in the clinical presentation of these two diseases, the respective ATPases function in precisely the same fashion within the cell. The different clinical features of each disease are the results of the tissue specific expression of these ATPases. In Wilson's disease, impaired biliary copper excretion leads to accumulation of this metal in the liver. When the capacity for hepatic storage is exceeded, cell death ensues, with copper release into the plasma resulting in hemolysis and deposition of copper in extrahepatic tissues. Affected patients usually present in the first or second decade of life with chronic hepatitis and cirrhosis or acute liver failure. Copper accumulation in the cornea results in Kayser-Fleischer rings. Neuropsychiatric symptoms are more common in adults and include dystonia, tremor, personality changes, and cognitive impairment as a results of copper accumulation in the basal ganglia and other brain regions. The diagnosis of Wilson's disease is confirmed by decreased serum ceruloplasmin, increased urinary copper, and elevated hepatic copper concentration. A large number of different mutations occur in the genes of patients with Wilson disease. Copper chelation drugs and zinc are effective in most cases. New treatment guidelines now advise physicians to start patients on zinc.