Gaucher's Disease

Forms of Disease

Three forms of GD have been reported. The form of disease determines the person's symptoms and their severity. According to data from the Gaucher Registry, type 1 accounts for 94 percent of cases. Fortunately, these symptoms often manifest later in life and are less severe than the other forms. That is why type 1 GD is called the adult form. People with type 1 GD may have enlargement of the liver and spleen with the potential for subsequent destruction, reduced platelet count, anemia, reduced white blood cell count, and lung disease. The clinical course is variable and can range from barely detectable to wheelchair confinement at an early age.

Forms 2 and 3 are much less common. They are not linked to the Jewish population. In addition to the symptoms suffered in type 1, GD patients with types 2 or 3 suffer neurologic squeal. Type 2, also called the infantile form, is fatal within the first three years of life. Type 3 GD, also called the juvenile form, progresses more slowly. However, it still results in neurologic problems, such as seizures and poor coordination.

Diagnosis

The best way to diagnose GD is with a genetic test. A doctor will send someone for this test if he or she is suspicious of GD. Some scenarios that may raise this suspicion are family history of GD, enlarged liver, enlarged spleen, or low platelet count.

Genetic Screening

Screening for type 1 GD is available. It is typically performed as part of a Jewish genetic screening panel, a battery of screening tests performed when a Jewish couple begins to plan for a family. This has brought up a number of ethical concerns. Will the knowledge of [Page 706]a couple's carrier status impact the decision to move forward with a family?

This carves out a niche for genetic counseling as more individuals are being screened. GD is inherited in an autosomal recessive pattern. If two parents are carriers for the same genetic mutation, the child has a 25 percent chance of having the disease. If one parent has the disease and the other does not, the child will be a carrier for GD.

Treatment

Imiglucerase (Cerezyme®, Genzyme) replaces the deficient ß glucocerbrosidase. It is used only in type 1 GD. Approximately 3,500 patients around the world are on this course of treatment. Enzyme replacement therapy is extremely costly, ranging from $250,000 to $600,000 annually, depending on the patient's body mass. Again, ethical issues arise. How much is society willing to pay in order to extend life? What social obligations, if any, does the pharmaceutical industry have? Very severe cases of GD may require splenectomy if the spleen has been damaged. This is done much less frequently since the approval of Imiglucerase.

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