WILSON DISEASE AND IDIOPATHIC COPPER TOXICOSIS

The pathogenic agent of both Wilson disease (WD) and non-Indian childh ood cirrhosis (which we term idiopathic copper toxicosis, or ICT) is c opper accumulating to excess in the liver. Inheritance of a pair of al leles of an autosomal recessive gene on chromosome 13 is necessary and sufficient to cause such copper accumulation in WD; reducing the diet ary intake of copper cannot prevent the development of WD. Zn contrast , the lethal accumulations of copper in children with ICT have been at tributed primarily to an increased dietary intake of copper. However, 64 124 child-year exposures of children under the age of 6 y to drinki ng water containing a copper concentration of approximate to 125.9 mu mol/L (8 mg/L) produced no deaths from any form of liver disease. More over, the ICT of seven infants was attributed primarily to drinking wa ter containing < 110.2 mu mol Cu/L. (7 mg/L) despite evidence of the p resence of a genetic defect in three of the patients, one of whom was exclusively breast-fed. These data suggest that ICT cannot be caused s olely by increased dietary intake of copper and occurs only in childre n with an unidentified genetic defect.