GD is caused by low levels of the glucocerebrosidase enzyme. There are two types of treatment available for GD1. The first is called "enzyme replacement therapy" (ERT) which involves providing a synthetic enzyme to take the place of the natural enzyme that does not work well in an affected person. ERTs are available for moderate to severe GD1. The synthetic enzyme is given as an intravenous (IV) drug. Regular IV infusions ERT have been demonstrated to be safe and effective in reversing low blood cell counts, in decreasing the size of the liver and spleen and can improve quality of life within the first year of treatment. Approximately 10% to 15% of people develop antibodies to the replacement enzymes, although in most cases these people remain symptom-free.
The second type of treatment is called "substrate reduction therapy" (SRT), and involves reducing the amount of work for the remaining enzyme. SRT is approved for people with mild to moderate GD1. SRT is taken by mouth, and helps decrease the enlarged liver and spleen, strengthen the bones, and may improve other symptoms as well.
People with GD1 and GD3 live longer than people with GD2. Over time, people with GD1 and GD3 may become resistant to the effect of treatments. In those cases, bone marrow transplantation may be recommended.
Other treatments may help relieve the symptoms of GD, but they won't combat the cause. For example, surgery to remove the spleen helps some patients because an enlarged spleen can destroy platelets as they pass through the spleen. Blood transfusions can treat severe anemia. Bone pain can be treated with pain medication. Sometimes, joint replacement surgery is needed. Medications that help increase bone density can also be helpful in some people. Of the medications that increase bone density, the most commonly used ones are the bisphosphonates, such as alendronate (Fosamax), ibandronate (Boniva) and risedronate (Actonel).