Copper is an essential
trace element required by all living organisms. Excess amounts of
copper, however, results in cellular damage. Disruptions to normal
copper homeostasis are hallmarks of three
genetic disorders:
Menkes disease,
occipital horn syndrome, and
Wilson's disease.
Menkes disease and
occipital horn syndrome are characterized by
copper deficiency. Typical features of
Menkes disease result from low
copper-dependent
enzyme activity. Standard treatment involves parenteral administration of
copper-histidine. If treatment is initiated before 2 months of age, neurodegeneration can be prevented, while
delayed treatment is utterly ineffective. Thus, neonatal mass screening should be implemented. Meanwhile, connective tissue disorders cannot be improved by
copper-histidine treatment. Combination
therapy with
copper-histidine injections and
oral administration of
disulfiram is being investigated.
Occipital horn syndrome characterized by connective tissue abnormalities is the mildest form of
Menkes disease. Treatment has not been conducted for this syndrome.
Wilson's disease is characterized by
copper toxicity that typically affects the hepatic and nervous systems severely. Various other symptoms are observed as well, yet its early diagnosis is sometimes difficult.
Chelating agents and
zinc are effective treatments, but are inefficient in most patients with
fulminant hepatic failure. In addition, some patients with neurological
Wilson's disease worsen or show poor response to
chelating agents. Since early treatment is critical, a screening system for
Wilson's disease should be implemented in infants. Patients with
Wilson's disease may be at risk of developing
hepatocellular carcinoma. Understanding the link between
Wilson's disease and
hepatocellular carcinoma will be beneficial for disease treatment and prevention.