Huntington’s disease (HD) is caused by a dominant genetic mutation which means that if one parent develops the disease there is a 50/50 chance of their child also having the gene responsible for causing the disease. This mutation involves the protein huntingtin and is an insertion of multiple glutamine amino acids into the protein sequence in an inappropriate location. Because of this insertion of multiple incorrect amino acids (the building blocks of proteins), these mutated proteins clump together and cause brain cells in a specific area of the brain to die. Death of these neurons, in the basal ganglia, lead to the symptoms of HD which include irritability, depression, anxiety, aggression, lack of coordination, muscle jerks, problems with balance, walking, speech and swallowing, cognitive decline, short-term memory loss, and eventually death. There are currently no cures or even treatments for the disease. Recently, there has been evidence that metal ions, specifically copper, are involved in or mediate the process of Huntington’s. Since diseases of copper overload where copper accumulates and has been shown to accumulate in the brain, this idea can be extended to HD where copper could have a role in the mutated proteins that aggregate in this disease. A paper from 2007 looked at this possibility and did various experiments to determine that copper was 1) able to interact well with the huntingtin protein, 2) copper was able to cause aggregation of the huntingtin protein 3) copper and iron levels were increased in mouse brains with HD and 4) and an enzyme that we know is sensitive to copper stops working as well in mouse brains with HD. All of this evidence highly supports the idea that copper is an essential metal ion in the progression of Huntington’s Disease, but more research is needed to fully determine its role, whether that ends up being a catalyst for disease progress or a substance that worsens the disease when in excess.
