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Glucosylsphingosine (Lyso Gb1)
Test Code14167
CPT Codes
82542
Preferred Specimen
0.5 mL plasma collected in an EDTA (lavender-top) tube
Minimum Volume
0.25 mL
Other Acceptable Specimens
Plasma collected in: Lithium heparin (green-top) tube, or sodium heparin (green-top) tube • Serum collected in a red-top tube (no gel)
Transport Temperature
Refrigerated (cold packs)
Specimen Stability
Room temperature: 72 hours
Refrigerated: 31 days
Frozen: 28 days
Refrigerated: 31 days
Frozen: 28 days
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Hemolysis • Serum separator tube (SST)
Methodology
Mass Spectrometry (MS)
FDA Status
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by FDA. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.
Setup Schedule
Set up: Wed; Report available: 7 days
Reference Range
| <18 years | ≤0.94 ng/mL |
| ≥18 years | ≤0.86 ng/mL |
Clinical Significance
Gaucher disease (GD) is one of the most frequent lysosomal disorders with a prevalence of 1:50,000 in the general population. It is characterized by a deficiency in the activity of the enzyme acid B-glucosidase, which leads to accumulation of glucocerebroside within lysosomes of macrophages, leading to hepatosplenomegaly, bone marrow suppression, and bone lesions. Depending on onset and symptoms, GD can be classified as non-neuronopathic, which is the mildest and most common phenotype in GD; the acute, neuronopathic form, which represents the severest form of the disease and is fatal within a few years; and the sub- acute, chronic neuronopathic form. Non-neuronopathic GD is the most common disease manifestation in the Ashkenazi Jewish population and with a frequency of up to 1:1,000. Genotype-phenotype correlations have been described in the literature. The most common examples are the mutation N370S usually detected in patients with non-neuronopathic GD carrying a milder burden of disease whereas e.g., the mutation L444P is more frequently seen in the more severe neuronopathic form of GD.
Recently, Lyso GL-1 (glucosyl-sphingolipid) has emerged as a specific biomarker for GD. It is generated from the accumulated substrate glucosylceramide (GL-1) by the action of acid ceramidase. Being soluble in nature, Lyso GL-1 exits the lysosomal system and accumulates in other organs. The molecule is postulated to play a role in various pathophysiological mechanisms including neuronal injury in Gaucher patients by deregulating signal transduction pathways via the inhibition of protein kinase C.
Recently, Lyso GL-1 (glucosyl-sphingolipid) has emerged as a specific biomarker for GD. It is generated from the accumulated substrate glucosylceramide (GL-1) by the action of acid ceramidase. Being soluble in nature, Lyso GL-1 exits the lysosomal system and accumulates in other organs. The molecule is postulated to play a role in various pathophysiological mechanisms including neuronal injury in Gaucher patients by deregulating signal transduction pathways via the inhibition of protein kinase C.
