Wilson disease is a genetic, or inherited condition. A mutation, or defect, in your ATP7B gene prevents your body from properly getting rid of extra copper in your system. Copper, which you consume in your diet, is one of the many minerals your body needs in small amounts. However, too much copper is toxic.
Normally, your liver sends excess copper out of your body in bile, the digestive juice your liver manufactures. Wilson disease prevents your liver from functioning normally. Instead of getting rid of the mineral, your liver starts storing it. Eventually, the buildup is more than the liver can hold, and the excess copper gets into your bloodstream and collects in other organs, even your eyes and brain. This buildup of copper begins when you're born, but it can take years or even decades for symptoms to appear.