Gaucher disease is caused by mutations in the GBA gene. The GBA gene is the gene that creates instructions for the body to make the enzyme beta-glucocerebrosidase. This enzyme is repsonsible for breaking down a substance called glucocerebroside within cells.
Because the gene is mutated, the production of the enzyme will either stop completely or be greatly reduced. This means that glucocerebroside will not be broken down into its components, glucose and ceramide.
When the substrate cannot be broken down, this leads to the build up of fat in many organs. More about the symptoms associated with this build up is on the next page.