Diagnosis and monitoring of Fabry disease
This test is used to diagnose and monitor patients with Fabry disease.
The following algorithms are available:
-Fabry Disease: Newborn Screen-Positive Follow-up
-Fabry Disease Diagnostic Testing Algorithm
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Globotriaosylsphingosine
Lyso-GB3
Anderson-Fabry Disease
GLA deficiency
Fabry Disease
The following algorithms are available:
-Fabry Disease: Newborn Screen-Positive Follow-up
-Fabry Disease Diagnostic Testing Algorithm
Serum
This test should not be used to determine carrier status. Order FABRZ / Fabry Disease, Full Gene Analysis, Varies for carrier testing.
1. Patient's age is required.
2. Reason for testing is required.
Question ID | Description | Answers |
---|---|---|
BG708 | Reason for Referral |
Rule out Fabry disease Follow-up of abnormal newborn screening Follow-up of known Fabry patient Not provided |
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
1. Biochemical Genetics Patient Information (T602)
2. If not ordering electronically, complete, print, and send a Biochemical Genetics Test Request (T798) with the specimen.
0.5 mL
Gross hemolysis | OK |
Gross lipemia | Reject |
Gross icterus | OK |
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum | Frozen (preferred) | 90 days | |
Refrigerated | 48 hours |
Diagnosis and monitoring of Fabry disease
This test is used to diagnose and monitor patients with Fabry disease.
The following algorithms are available:
-Fabry Disease: Newborn Screen-Positive Follow-up
-Fabry Disease Diagnostic Testing Algorithm
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 kidney 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. 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.
< or =1.0 ng/mL
Elevation of globotriaosylsphingosine is diagnostic for Fabry disease.
Carrier detection using globotriaosylsphingosine (LGb3) is unreliable.
Some patients with Fabry disease may, and all individuals with pseudodeficiency of alpha-galactosidase enzyme, have normal concentrations of LGb3.
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, Everman DB, Mirzaa GM, et al, eds. GeneReviews [Internet]. University of Washington, Seattle; 2002. Updated January 27, 2022. Accessed January 17, 2023. 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
5. Weidemann F, Beer M, Kralewski M, Siwy J, Kampmann C: Early detection of organ involvement in Fabry disease by biomarker assessment in conjunction with LGE cardiac MRI: results from the SOPHIA study. Mol Genet Metab. 2019 Feb;126(2):169-182
Internal standard is added to the serum. Globotriaosylsphingosine (LGb3) is extracted from the serum prior to injection onto a liquid chromatography tandem mass spectrometry (LC-MS/MS) system. Following chromatographic isolation, the concentration is measured by MS/MS analysis in the selected reaction monitoring positive mode. The ratio of extracted peak area to internal standard is utilized to calculate the concentration of LGb3 in the sample.(Unpublished Mayo method)
Thursday
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.
82542
Test Id | Test Order Name | Order LOINC Value |
---|---|---|
LGB3S | Lyso-GB3, S | 90234-6 |
Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
---|---|---|
BG708 | Reason for Referral | 42349-1 |
65532 | Lyso-GB3, S | 90234-6 |
113176 | Interpretation (LGB3S) | 59462-2 |
113177 | Reviewed By | 18771-6 |
Change Type | Effective Date |
---|---|
Test Changes - Specimen Information | 2023-12-19 |
Test Status - Test Resumed | 2023-02-02 |