There are several subtypes of Gaucher disease. Type 1 Gaucher disease is the most common Ashkenazi Jewish genetic disease. It is a highly variable condition with onset of symptoms typically occurring between adolescence and early adulthood. This disease is characterized by painful bone deterioration, an enlarged spleen and liver, and a decreased production of blood cells resulting in anemia, increased susceptibility to infections, easy bruising and increased bleeding tendency.
Gaucher disease Types 2 and 3 are much more rare. In addition to the symptoms listed above, affected individuals also have neurological problems. Onset of Types 2 and 3 is typically in childhood. Gaucher disease is caused by decreased amounts of an enzyme called beta-glucocerebrosidase. This enzyme deficiency leads to the build-up of a fatty substance, primarily in the liver, spleen, and bone marrow.
There is a highly effective treatment for Type 1 Gaucher disease, known as enzyme replacement therapy. Regular intravenous infusion with imiglucerase (Cerezyme) can reverse the symptoms of the disease and prevent new symptoms from appearing.
For those with Gaucher disease for whom enzyme replacement therapy is not an option (due to allergy, hypersensitivity, or difficulty with IV administration) there is an oral medication, known as Miglustat, which has been more recently approved as another treatment modality. Several studies have shown that people with Gaucher disease who were treated with Miglustat had significant improvement of their symptoms.
One in 14 people with Ashkenazi Jewish ancestry is a carrier of Type 1 Gaucher disease.
How Is Gaucher Disease Inherited?
The cells in our body typically contain 46 chromosomes. Each chromosome is a package that holds hundreds of genes. These genes contain the all of the blueprints for our growth and development; they are the instructions that make us who we are. All of our chromosomes (and the genes that are located on these chromosomes) come in pairs. We inherit one chromosome of each pair from our mother and the other chromosome of the pair from our father.
;)
When there is a change in a gene (called a mutation) the instructions it contains are no longer correct and the gene cannot carry out its function. Individuals with Gaucher disease have two copies of a mutation, one copy inherited from each parent. Neither gene in the pair is working correctly, which causes the symptoms of the disease.
A carrier of Gaucher disease is a person who has a mutation in one gene of the pair. Carriers are unaffected with the disease because the properly working gene is able to compensate for the gene that contains the mutation.
When two parents are carriers of Gaucher disease:
- there is a 1 in 4 (25%) chance of having a child with Gaucher disease,
- there is a 1 in 2 (50%) chance of having a child who is an unaffected carrier like the parents,
- and, there is 1 in 4 (25%) chance of having a child who is unaffected and is not carrier.
When one parent is a carrier of Gaucher disease and the other parent is not a carrier, they are not at increased risk to have a child with Gaucher disease. Instead, there is a 1 in 2 (50%) chance of having a child with is an unaffected carrier like the one parent.
What This Test Tells You
This test tells whether you are a carrier of Gaucher disease. It looks for 8 mutations known to cause Gaucher disease. It detects 95% of mutations for Type 1 Gaucher disease and 50-60% of mutations for Types 2 and 3 in the GBA gene, in people of Ashkenazi Jewish descent. This test also detects 75% of mutations for Type 1 Gaucher disease in non-Jewish Caucasians.
It is possible, because of the variability associated with this condition, that testing may reveal that you have two gene mutations and are affected with Gaucher disease even if you are currently asymptomatic. In this case an evaluation at one of the Comprehensive Gaucher Centers would be recommended to determine the need for treatment.
How Testing Works
Testing with DNA Direct is quick, convenient, and can be done in the privacy of your home. It can also be anonymous if you wish. How to order online and consult with our genetic experts: DNA Direct's Expert Services
References:
1. Beutler E, Nguyen NJ, Henneberger MW, Smolec JM, McPherson RA, West C, Gelbart T. 1993. Gaucher disease: Gene frequencies in the Ashkenazi Jewish population. Am J Hum Genet 52:85-88.2. Grabowski G. 1997. Gaucher disease: Gene frequencies and genotype/phenotype correlations. Genetic Testing 1:5-12.
3. Horowitz M, Pasmanik-Chor M, Borochowitz Z et al. 1998. Prevalence of glucocerebrosidase mutations in the Israeli Ashkenazi Jewish population. Hum Mutat 12:240-244.
