"Wilson's disease is an autosomal recessive disorder of Cu metabolism, caused by mutations within the ATP7B gene which is located on chromosome 13q14.1. ATP7B gene causes impaired biliary Cu excretion resulting in hepatic copper toxicity and subsequent multisystem disease involving in liver, brain, cornea, skeleton and rarely the heart. In childhood hepatic manifestations predominate with a highly variable spectrum ranging from self-limiting hepatitis to fulminant hepatic failure. Pathogenesis of Wilson's disease: Hepatocytes are the primary site of Cu uptake and accumulation in the liver. They sense the Cu status in the cytoplasm and regulate Cu excretion into the bile depending on the intracellular concentration of this metal. This regulation is accomplished by the protein product of the ATP7B gene.
Copper transporting P-type protein (ATPase) that transports Cu across cell membranes is ATP7B. The ATP7B protein has two functions: (1) Forming an active Cu channel in TGN to move Cu from cytosol to the apo-protein of ceruloplasmin; and (2) Cu export into the bile canaliculus. This explains the two cardinal abnormalities in WD: (1) Failure of ceruloplasmin synthesis; and (2); Failure of Cu excretion into.
Copper accumulation might be associated with increased oxidative stress and damage within target tissues where Cu concentrations are high. High intra-mitochondrial Cu concentrations might increase free radical generation. Mitochondrial changes including abnormal morphology have been identified in liver from patients with WD. There is evidence of a 33-fold increase of mitochondrial Cu and of oxidative damage in the liver in these patients. Also, there is significant decrease in mitochondrial enzyme activities in livers of patients with WD as compared with patients with cholestatic liver diseases with high copper accumulation. This implies that oxidative damage and mitochondrial dysfunction are important in the pathogenesis of WD.
(Ibrahim NL- Study of Serum Copper and Iron in Children with Chronic Liver Diseases)."
Last date updated on June, 2014