Gaucher Disease: Beta-glucosidase Enzyme Analysis

Turnaround Time

2 weeks

CPT Code(s)

82963

Cost

$200

Enzymes

• Gaucher Disease

Gaucher disease, a lysosomal storage disorder, can present with a wide spectrum of severity ranging from a perinatal lethal phenotype to asymptomatic. There are three primary types with two additional subtypes, all categorized by differences in the clinical presentation of the patient. Hepatosplenomegaly, pulmonary disease, and cytopenia are also common for most types of Gaucher disease. Patients with Gaucher disease type 1 have varying degrees and types of bone disease as the primary feature, but do not have any central nervous system involvement. Gaucher disease types 2 and 3 present with primary neurologic disease. Type 2 and 3 are distinguished based on age of onset and disease progression. Patients with type 2 typically have an earlier onset before age 2, rapid disease progression, and early death. Type 3 is characterized by a slower disease course with patients living into adulthood. Neurologic findings for types 2 & 3 include bulbar signs, pyramidal signs, oculomotor apraxia, seizures, as well as dementia and ataxia in later disease stages. The perinatal lethal form may present as nonimmune hydrops fetalis or with pyramidal neurologic signs and ichthyosiform skin changes. The cardiovascular form is characterized by primarily by calcification of mitral and aortic values with other minor findings.

Biomarker analysis of chitotriosidase can be used to monitor disease progression for affected individuals including those receiving enzyme replacement therapy.

4-methylumbelliferyl substrate

Enzyme activity can be measured in leukocytes, cultured fibroblasts, or dried blood spots. For leukocytes, please send 5-10 ml of whole blood in a green top (sodium heparin) tube. For dried blood spot collection, a minimum of three circles need to be filled in. Each circle should contain one drop of blood (about 100 microliters). See the link below for additional sample collection and handling instructions.

Whole blood samples (for leukocyte analysis) should be shipped at ambient temperature and must arrive at the laboratory within 24 hours of specimen collection. Cultured fibroblasts should be sent overnight at room temperature. For a dried blood spot: When the sample has dried 3-4 hours, fold cover at score line, over sample, and tuck into flap. Samples can be mailed at ambient temperature.