What is Copper Storage Disease?
Copper storage disease is a genetic condition in which excessive levels of the mineral copper builds up within tissue. Also known as Wilson’s disease, this degenerative disorder can impact a variety of organisms, but is most common in humans and dog breeds such as the Bedlington Terrier. Symptoms of the disorder result in a number of neurological and psychiatric problems. Most notably, however, is the development of liver disease, which ultimately leads to potential failure.
Genetic Causes of Wilson’s Disease
For 90 percent of people affected by copper storage disease there is a causal link to a mutated gene located on the 13th chromosome, specifically position 13q14.3. 60 percent of these mutations are homozygous, while the remainder are heterozygous. Called ATP7B, this gene has been shown to mutate at least 300 different ways to create this condition. However, geneticists have linked specific types of mutations to certain regions around the world, leading to theories that specific haplogroups experience different genetic causes of Wilson’s disease.
Fortunately, a variation of the PRNP gene releases a prion protein in the brain that delays the development of copper storage disease. Additionally, in order for the genetic disorder to develop, a person must inherit the gene from both parents, which is transferred in a recessive pattern.
Pathology of Excessive Copper Deposits
The body naturally accumulates copper from the digestive system via a protein called copper membrane transporter 1 (CMT1). It is used in a number of enzymes, specifically for brain function. In a normal person, excessive levels of the mineral are removed by the non-mutated ATP7B gene and placed into an individual’s bile. Without the removal of copper, however, oxidization of the hemoglobin can occur, damaging the cell membrane of the nervous system and liver by inhibiting the energy distribution of red blood cells.
Symptoms of Liver Disease and Neurological Disorders
Copper storage disease can be most readily identified by the existence of liver disease. If a person is suffering from high levels of tiredness, hypertension or cirrhosis, it is possible that Copper storage disease is responsible. Unfortunately, roughly five percent of all patients develop acute liver failure before a proper diagnosis can be determined.
In the case of neurological disorders, a variety of issues can develop that lead to a diagnosis. Minor signs such as clumsiness or slurred speech can be early warning signs. But as the disease develops further, major problems such as tremors and seizures are commonplace.
Treatments for Copper Storage Disease
Outside of a complete liver transplant, which is the only known way to fully cure Copper storage disease, a variety of treatment options are available to patients suffering from the disorder. The first level of treatment comes in the form of diet control. Foods low in copper, such as shellfish, mushrooms, fruit and nuts are the best options. A drug known as penicillamine can also be administered. Penicillamine binds with copper in the bloodstream and causes it to be excreted through urination. Zinc can also be used to similar effect. The mineral, in the form of zinc acetate, causes a protein known as metallothionein to bind to copper and prevent its absorption by the liver.
“What is Wilson’s Disease” National Digestive Diseases Information Clearinghouse
“Wilson’s Disease” Mayo Clinic
PBB Protein ATP7B image. (Supplied by ProteinBoxBot at Wikimedia Commons; Public Domain; https://upload.wikimedia.org/wikipedia/commons/a/a7/PBB_Protein_ATP7B_image.jpg)