About Gaucher Disease
Gaucher disease is a group of three rare inherited genetic disorders characterized by the lack of the glucocerebrosidase enzyme. Without the glucocerebrosidase enzyme, too much fat accumulates in the liver, lungs, bones, spleen, and, sometimes, the brain. When excess fat accumulates in the body's organs, it prevents them from functioning properly.
Why it is Problematic
Type I is the mildest and most common form of Gaucher disease, representing roughly 90% of all cases and causing liver and spleen enlargement, pain in the bones, broken bones, and kidney or lung problems. Type I may occur at any age.
Type II, which often appears in infants, is a more serious form of Gaucher disease that affects the brain. Type II can result in severe damage to the brain and even death.
Type III typically appears in childhood or adolescence, causing possible liver, spleen, and gradually, brain enlargement.
Causes and Risk Factors
Gaucher disease is an inherited genetic disorder caused by an autosomal recessive gene. An individual with Gaucher disease has received two copies of the mutated gene, one from each parent. Gaucher disease requires two copies (homozygous) of the mutation in order for the disease to become active. Parent carriers with only one copy of the mutation (heterozygous) do not have Gaucher disease.
There is a 1 in 4 chance that the child of two carrier (heterozygous) parents will be born with Gaucher disease, and a 50% chance that the child will be a carrier.
The risk of being a carrier of Type I Gaucher disease, increases in those of Central or Eastern European Jewish(Ashkenazi) descent. Type II and Type III occur in individuals of all ethnic backgrounds, with the exception of very specific sector of Type III which is most commonly found in those of Swedish ancestry.
A family history of Gaucher disease increases an individual's chances of having Gaucher's disease or being a carrier for the disease.
Symptoms of Gaucher disease are variable depending on the type and the individual.
Type I symptoms include:
- An enlarged liver (hepatomegaly)
- Excessive fatigue
- Yellow eye spots
- Easy bruising
- Decrease in healthy red blood cells
- Skeletal abnormalities
- Bone fractures
- Bone pain
- Delayed puberty
Type II symptoms include:
- Brain conditions and intellectual disabilities
- Loss of muscle coordination
- Abnormal eye movement
If you or someone you know is experiencing symptoms of Gaucher disease, contact your doctor immediately.
If Gaucher disease is suspected, or if it runs in your family, a doctor can perform tests to check for the Gaucher mutation.
Genetic testing uses blood tests to examine portions of an individual's DNA for genetic mutations. There are currently 22 known mutations linked to Gaucher disease. Genetic testing may also be used to assist in determining the type of Gaucher disease. Since it is unlikely that all of the genes associated with Gaucher's disease have been identified, this test may be considered less diagnostically definitive.
Dual energy X-ray absorptiometry (DXA) is a low-level X-ray used to measure bone density and any changes in bone density over time. This method may be useful in diagnosing Gaucher disease.
Magnetic resonance imaging (MRI) is a magnetic field and radio waves that create images of the liver and spleen for close-up viewing on a monitor.
Genetic counseling for preconception screening and prenatal testing may be recommended for women who are known carriers or who have a family history of Gaucher's disease. A doctor can perform a blood test prior to or after conception to determine a child's risk for inheriting Gaucher disease. If one or both parents have a history of Gaucher disease or are of Central or Eastern European Jewish (Ashkenazi) descent, genetic counseling is recommended.
For women who are confirmed carriers of Gaucher disease, prenatal testing for genetic mutations is recommended to help determine the risk of the fetus. Prenatal tests (amniocentesis, or placenta tissue evaluation chorionic villus sampling) evaluate cells in the amniotic fluid can detect Gaucher disease.
If you want to have these tests performed, speak with your doctor, who can refer you to a genetic counselor. A genetic counselor can discuss the benefits and risks associated with these tests.
Treatment and Prevention
Some individuals with Type I Gaucher disease do not require treatment if their symptoms are mild. There is no specific treatment for Type II.
Enzyme replacement therapy is used to treat Type I and Type III. This therapy uses an IV to supply high doses of an artificial enzyme replacement at two-week intervals. This treatment is often successful for Type I and, to a lesser degree, for Type III.
Enzyme replacement therapy can reduce liver and spleen enlargement, help to resolve blood abnormalities, and improve bone density. It is unclear whether this treatment is effective for neurological problems. Some individuals are allergic or hypersensitive to this type of treatment.
Pregnancy may intensify the symptoms of Gaucher disease, although typically these do not affect the success of the pregnancy. If you are pregnant, talk to your doctor about whether to continue enzyme replacement therapy during your pregnancy.
Medication taken orally is sometimes used in the treatment of Gaucher disease. Medication can interfere with glucocerebrosides in Type I of the disease. There are also many adverse side effects associated with this treatment, including reproductive impairment.
Bone marrow transplants may be necessary in severe cases of Gaucher disease. This process entails the removal of damaged blood-forming cells within the bones and replacement with healthy cells. This can reverse many of the symptoms associated with Gaucher disease. Due to the high risks associated with bone marrow transplants, this procedure for Gaucher disease is performed infrequently.
Individuals with mild Gaucher disease, especially those who develop the disease in adulthood, have a nearly normal life expectancy. Children who develop the condition in infancy typically do not live past the age of 2. Children with Type III who live into their teens often live for many subsequent years.
Type I affects around 1 person in 50,000-100,000 of the general population, but 1 in 500-1000 of those of Ashkenazi Jewish descent. About 1 in 15 individuals of Ashkenazi descent are carriers for Type I of Gaucher disease.
Type II and Type III Gaucher disease are both more rare.