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Test ID LGB3S Globotriaosylsphingosine, Serum


Ordering Guidance


This test is not useful for determining carrier status. Order FABRZ / Fabry Disease, Full Gene Analysis, Varies 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 a Biochemical Genetics Test Request (T798) with the specimen.

Useful For

Diagnosis and monitoring of Fabry disease

Method Name

Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)

Reporting Name

Lyso-GB3, S

Specimen Type

Serum

Specimen 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. Female patients who are carriers 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 3000 infants detected via newborn screening to 1 in 10,000 male patients diagnosed after onset of symptoms.

 

Unless irreversible damage has already occurred, treatment with enzyme replacement therapy leads 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 (AGAW / 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, Varies) allows for detection of the disease-causing variant in male and female patients. Molecular genetic testing is the recommended diagnostic test for female patients as alpha-galactosidase activity may be in the normal range in those affected.

 

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 of LGb3, may provide additional diagnostic information in the evaluation of uncertain cases, such as in asymptomatic heterozygous female patients, 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 is diagnostic for Fabry disease.

Clinical Reference

1. Aerts JM, Groener JE, Kuiper S, et al: Elevated globotriaosylsphingosine is a hallmark of Fabry disease. Proc Natl Acad Sci USA. 2008 Feb 26;105(8)2812-2817

2. Mehta A, Hughes DA: Fabry disease. In: Adam MP, Ardinger HH, Pagon RA, eds. GeneReviews [Internet].. University of Washington, Seattle; 2002. Updated January 5, 2017. Accessed August 12, 2021. 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 Oct;22(5):555-564

4. Laney DA, Peck DS, Atherton AM, et al: Fabry disease in infancy and early childhood: a systematic literature review. Genet Med. 2015 May;17(5):323-330

Day(s) Performed

Thursday

Report Available

8 to 15 days

Test 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 US 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
Mayo Clinic Laboratories | Pediatric Catalog Additional Information:

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