Test ID LGB3S Globotriaosylsphingosine, Serum
Advisory Information
This test is not useful for determining carrier status. Order FABRZ / Fabry Disease, Full Gene Analysis for carrier testing.
Necessary Information
1. Patient’s age is required.
2. Reason for referral is required.
Specimen Required
Collection Container/Tube:
Preferred: Red top
Acceptable: Serum gel
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Forms
1. Biochemical Genetics Patient Information (T602) in Special Instructions.
2. If not ordering electronically, complete, print, and send an Inborn Errors of Metabolism Test Request (T798) with the specimen.
Useful For
Diagnosis and monitoring of Fabry disease
Testing Algorithm
The following algorithms are available in Special Instructions:
Special Instructions
Method Name
Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)
Reporting Name
Lyso-GB3, SSpecimen Type
SerumSpecimen Minimum Volume
0.5 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum | Frozen (preferred) | 90 days | |
Refrigerated | 72 hours |
Clinical Information
Fabry disease is an X-linked recessive lysosomal storage disorder caused by a deficiency of the enzyme alpha-galactosidase A (alpha-Gal A). Reduced enzyme activity results in accumulation of glycosphingolipids in the lysosomes throughout the body, in particular, the kidney, heart, and brain. Severity and onset of symptoms are dependent on the residual enzyme activity. Symptoms may include acroparesthesias (pain crises), multiple angiokeratomas, reduced or absent sweating, corneal opacity, renal insufficiency leading to end-stage renal disease, and cardiac and cerebrovascular disease. There are renal and cardiac variant forms of Fabry disease that may be underdiagnosed. Heterozygous females of Fabry disease can have clinical presentations ranging from asymptomatic to severely affected, and they may have alpha-Gal A activity in the normal range. The estimated incidence varies from 1 in 3,000 infants detected via newborn screening to 1 in 10,000 males diagnosed after onset of symptoms.
Unless irreversible damage has already occurred, treatment with enzyme replacement therapy (ERT) has led to significant clinical improvement in affected individuals. For this reason, early diagnosis and treatment are desirable, and in a few US states early detection of Fabry disease through newborn screening has been implemented.
Absent or reduced alpha-Gal A in blood spots, leukocytes (AGA / Alpha-Galactosidase, Leukocytes), or serum (AGAS / Alpha-Galactosidase, Serum) can indicate a diagnosis of classic or variant Fabry disease. Molecular sequence analysis of the GLA gene (FABRZ / Fabry Disease, Full Gene Analysis) allows for detection of the disease-causing mutation in males and females. Molecular genetic testing is the recommended diagnostic test for females as alpha-galactosidase activity may be in the normal range in an affected female patient.Â
The glycosphingolipid, globotriaosylsphingosine (LGb3), may be elevated in symptomatic patients and supports a diagnosis of Fabry disease. It may also be helpful as a tool for monitoring disease progression as well as determining treatment response in known patients. In addition, measurement or globotriaosylsphingosine (LGb3), may provide additional diagnostic information in the evaluation of uncertain cases, such as in asymptomatic heterozygous females, individuals with novel GLA variants of unclear clinical significance, as well as asymptomatic patients identified by family screening.
Reference Values
≤1.0 ng/mL
Interpretation
Elevation of globotriaosylsphingosine (Lyso-GB3)is diagnostic for Fabry disease.
Clinical Reference
1. Aerts JM, Groener JE, Kuiper S, et al:Â Elevated globotriaosylsphingosine is a hallmark of Fabry disease. Proc Natl Acad Sci USA 2008;105(8)2812-2817
2. Mehta A, Hughes DA: Fabry Disease. In GeneReviews. 2002 Aug 5, Updated 2013 Oct 17. Edited by RA Pagon, MP Adam, HH Ardinger, et al: Seattle, WA. University of Washington, Seattle; 1993-2015. Accessed 6/21/17. Available at www.ncbi.nlm.nih.gov/books/NBK1292/
3. Laney DA, Bennett RL, Clarke V, et al: Fabry disease practice guidelines: recommendations of the National Society of Genetic Counselors. J Genet Couns 2013;22:555-564
4. Laney DA, Peck DS, Atherton AM, et al: Fabry disease in infancy and early childhood: a systematic literature review. Genet Med 17(5) 323-330. Accessed 6/21/17. Available at www.nature.com/gim/journal/vaop/ncurrent/pdf/gim2014120a.pdf
Day(s) and Time(s) Performed
Varies
Analytic Time
8 daysTest Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.CPT Code Information
82542
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
LGB3S | Lyso-GB3, S | 90234-6 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
BG708 | Reason for Referral | 42349-1 |
65532 | Lyso-GB3, S | 90234-6 |
113176 | Interpretation (LGB3S) | 59462-2 |
113177 | Reviewed By | 18771-6 |
mcl-newborn