Wilson's disease is an inborn error of copper metabolism, characterised by 
raised liver-copper concentrations and low serum levels of copper and 
caeruloplasmin. The autosomal recessive mode of inheritance strongly suggests 
that mutation of a single gene causes the impairment of both caeruloplasmin 
synthesis and biliary copper excretion. The normal infant is born with the 
biochemical features of Wilson's disease (very high liver-copper levels and low 
serum copper and caeruloplasmin). Induction of normal copper metabolism after 
birth results in a fall in liver-copper concentrations and rise in serum 
caeruloplasmin. The repression of normal copper metabolism in the fetus and its 
induction after birth is probably regulated by a controller gene. It is 
suggested that mutation of a controller rather than a structural gene underlies 
the pathogenesis of Wilson's disease and that the disease results from failure 
to switch from the positive copper balance of the fetus to the normal copper 
balance of the child.