Inherited Copper Transport Disorders: Biochemical Mechanisms, Diagnosis, and Treatment

Hiroko      Kodama; Chie      Fujisawa; Wattanaporn      Bhadhprasit

doi:10.2174/138920012799320455

Abstract

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 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 should be implemented. Meanwhile, connective tissue disorders cannot be improved by copper-histidine treatment. Combination with copper-histidine injections and oral administration of disulfiram is being investigated. Occipital horn syndrome characterized 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.

Keywords: Menkes disease, Wilson's disease, occipital horn syndrome, ATP7A, ATP7B, disulfiram, zinc, trientine, copper homeostasis, neurodegeneration