Gaucher's disease

Gaucher's disease is named after the French doctor Philippe Gaucher who first described it in 1882. Gaucher's is a genetic disease in which a fatty substance accumulates in cells and certain organs of the body. Gaucher's is a hereditary deficiency of the enzyme ‘glucocerebrosidase' which acts on a fatty substance ‘glucocerebroside', which accumulates particularly in the white cells. Glucocerebroside collects in the spleen, liver, kidneys, lungs, brain and in bone marrow.

Symptoms of Gaucher's disease

Neurological complications
Enlarged spleen and liver
Skeletal disorders
Lymph nodes swelling and joints
Distended abdomen
Brownish tint in skin
Anemia
Low blood platelets
Yellow fatty deposits on the white of the eye
Painful bone lesions
Persons with Gaucher's disease are more susceptible to infections.

Gaucher's disease types

Type 1: This is the most common form of the disease which causes enlargement of liver and spleen, causes pain and breaks bones, and also causes lung and kidney problems. However, this does not involve the brain. Type 1 Gaucher's can occur at any age.

Type 2: This can cause severe damage of the brain and it appears mostly among infants. Children affected with Gaucher's die by age 2.

Type 3: Liver and spleen enlargement occur in this type and there are some signs of brain involvement though it is gradual. Although Gaucher's disease has no cure, there are treatment options for types 1 and 3. Enzyme replacement therapy is usually very effective in these types. However, treatment options for type 2 are very minimal.

Causes of Gaucher's disease

As described, Gaucher's disease is a rare and inherited disorder and build up of the enzyme glucocerebroside prevents the other organs in the body to function properly. The carrier rate among Ashkenazi Jews is almost 8.9% while the incidence at birth is 1 in 450. All the three forms of Gaucher's disease are caused by glucocerebrosidase activity deficiency. This is due to mutations in GBA, a structural gene that encodes the enzyme.

Diagnosis of Gaucher's disease

Normally the couples are tested for the Gaucher's disease. Blood samples are diagnosed and the level of enzyme responsible for Gaucher is measured. Gaucher gene can be analyzed at the molecular level. Affected individuals have two Gaucher genes and low enzyme levels when the other is a non carrier. Enzyme testing as a means of carrier identifications for Gaucher's disease is about 90% accurate. As such there could be an overlap in the range of enzyme activity values between non-carriers of the disease and the carriers. Hence, use of direct molecular DNA testing is more reliable and almost 98% accurate.

During pregnancy, all types Gaucher's disease can be detected through procedures called amniocentesis. Prenatal diagnosis is available for those who are at risk for having a child with Gaucher's.

Treatment

Spleen removal and bone marrow transplants were adopted previously but with substantial risks. Enzyme replacement therapy has been made available recently to combat the underlying problems in Gaucher's disease. Although originally the enzyme has been placentally derived, since 1994 Cerezyme, a recombination of form of acid beta glucosidose, which is FDA approved has been used for the treatment of symptomatic Gaucher's disease. Here regular intravenous infusion of enzyme which has been biochemically modified is done so as to target the Gaucher cell. However, enzyme therapy is complicated as the minimal effective dosage and optimal frequency of administration has not been established. Therefore, it calls for a very careful and coordinated management by physicians with special expertise in Gaucher's disease.