Gaucher Disease

Inherited Storage Disorder

Gaucher disease is an inherited storage disorder. In Gaucher disease, a specific enzyme is deficient. This deficiency allows a fatty substance known as glucocerebroside to build up to toxic levels in the spleen, liver, lungs, bone marrow, and sometimes in the brain. Gaucher disease is genetically inherited in an autosomal recessive pattern, meaning that a child must inherit two copies of the disease gene mutation -- one from each parent -- to be born with the disease. Gaucher disease affects both males and females.

There are three types of Gaucher disease. The Type 1 form is often called the adult form because its symptoms can begin at any age. Although Type 1 occurs worldwide in people of all ethnic backgrounds, it is most prevalent in the Ashkenazi Jewish population (Jews of Eastern European ancestry). Among this group, Gaucher disease occurs at a rate of 1 in 450 births, and is the most common genetic disease affecting Jewish people.

Type 2 Gaucher disease is usually diagnosed in infancy and is the most rare form of the disease. It also occurs worldwide in people of all ethnic backgrounds, and is estimated to occur in 1 in 100,000 births.

In Type 3 Gaucher disease, symptoms appear later in childhood than in Type 2. Type 3 also occurs in people of all ethnic backgrounds. It is estimated to occur in 1 in 50,000 births.

Symptoms

The most common symptoms of Gaucher Type 1 disease are:

• enlarged liver and spleen
• fatigue due to anemia
• low blood platelets, which leads to easy bruising and nosebleeds
• bone pain
• bone deterioration and weakening (osteoporosis)

There may also be lung and kidney impairment but there is no brain involvement. In Types 2 and 3 Gaucher disease, the brain and nervous system are affected, so additional symptoms include:

• lack of coordination (ataxia)
• brain damage
• seizures

The symptoms of Type 2 Gaucher disease begin in infancy, usually by age 3 months. The symptoms of Type 3 Gaucher disease come on more slowly and appear later in childhood than Type 2.

Diagnosis

A diagnosis of Gaucher disease may be suggested by the symptoms. A special blood test called an enzyme assay can measure glucocerebrosidase (GC) activity. In Gaucher disease, the GC levels will be very low, and would confirm the diagnosis.

Genetic testing for Gaucher disease can be done using a blood or saliva sample. There are four common mutations of the gene responsible for Gaucher disease. Testing for these four mutations detects 90 to 95% of the mutations associated with Gaucher disease in the Ashkenazi Jewish population and 50 to 75% of the mutations associated with the disease in other people. Genetic testing also may be helpful in determining which type of Gaucher disease is present. Family members can be tested to see who may have the Gaucher disease gene.

Treatment

There is as yet no complete cure for Gaucher disease. For people with Gaucher disease Types 1 and 3, a drug called Cerezyme (imiglucerase) replaces the deficient enzyme in the disease and relieves many of its symptoms. It is important to begin this enzyme replacement therapy before there are significant organ or bone changes. The treatment can’t undo the severe brain damage that may occur in Types 2 and 3. Children with Gaucher disease Type 2 have the most severe impairment and usually do not live past 2 to 3 years of age.

_Sources:

"NINDS Gaucher's Disease Information Page." Disorders A - Z. 07 Feb 2008. National Institute for Neurological Disorders and Stroke. 24 Feb 2009

"Gaucher Disease." Gaucher Disease Information. National Gaucher Foundation. 24 Feb 2009