Test Catalog

Test Id : GBAZ

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Gaucher Disease, Full Gene Analysis, Varies

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Overview

Test Catalog

Useful For
Suggests clinical disorders or settings where the test may be helpful

Confirmation of a diagnosis of Gaucher disease

 

Carrier screening in cases where there is a family history of Gaucher disease, but an affected individual is not available for testing or disease-causing alterations have not been identified

Genetics Test Information
Provides information that may help with selection of the correct genetic test or proper submission of the test request

Testing includes full gene sequencing of the GBA gene.

 

Risk alleles for Parkinson disease with no known beta-glucocerebrosidase enzyme reduction or Gaucher disease association will only be reported in patients over 18 years old unless otherwise requested.

Reflex Tests
Lists tests that may or may not be performed, at an additional charge, depending on the result and interpretation of the initial tests.

Test Id Reporting Name Available Separately Always Performed
CULFB Fibroblast Culture for Genetic Test Yes No

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

For skin biopsy or cultured fibroblast specimens, fibroblast culture testing will be performed at an additional charge. If viable cells are not obtained, the client will be notified.

 

For more information see Newborn Screen Follow-up for Gaucher Disease.

 

If the patient has abnormal newborn screening results for Gaucher disease, refer to the appropriate American College of Medical Genetics and Genomics Newborn Screening ACT Sheet.(1)

Method Name
A short description of the method used to perform the test

Polymerase Chain Reaction (PCR) followed by DNA Sequencing

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.

Yes

Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

Gaucher Disease, Full Gene Analysis

Aliases
Lists additional common names for a test, as an aid in searching

GBAMS

Beta-glucocerebrosidase deficiency

Beta-Glucosidase

GBA

GBA Gene

Glucocerebrosidase

Glucosidase

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

For skin biopsy or cultured fibroblast specimens, fibroblast culture testing will be performed at an additional charge. If viable cells are not obtained, the client will be notified.

 

For more information see Newborn Screen Follow-up for Gaucher Disease.

 

If the patient has abnormal newborn screening results for Gaucher disease, refer to the appropriate American College of Medical Genetics and Genomics Newborn Screening ACT Sheet.(1)

Specimen Type
Describes the specimen type validated for testing

Varies

Ordering Guidance

This is not the preferred genetic test for carrier screening or diagnosis in individuals of Ashkenazi Jewish ancestry. For these situations, order GAUP / Gaucher Disease, Mutation Analysis, GBA, Varies.

 

For diagnostic testing in potentially affected individuals, enzyme testing should be performed prior to molecular genetic analysis. Order GBAW / Beta-Glucosidase, Leukocytes.

 

For ongoing therapeutic monitoring, order GPSY / Glucopsychosine, Blood Spot.

Shipping Instructions

Specimen preferred to arrive within 96 hours of collection.

Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Patient Preparation: A previous bone marrow transplant from an allogenic donor will interfere with testing. Call 800-533-1710 for instructions for testing patients who have received a bone marrow transplant.

 

Submit only 1 of the following specimens:

 

Specimen Type: Whole blood

Container/Tube:

Preferred: Lavender top (EDTA) or yellow top (ACD)

Acceptable: Any anticoagulant

Specimen Volume: 3 mL

Collection Instructions:

1. Invert several times to mix blood.

2. Send specimen in original tube.

Specimen Stability Information: Ambient (preferred)/Refrigerated

 

Specimen Type: Cultured fibroblasts

Container/Tube: T-75 or T-25 flask

Specimen Volume: 1 Full T-75 or 2 full T-25 flasks

Specimen Stability Information: Ambient (preferred)/Refrigerated <24 hours

Additional information: A separate culture charge will be assessed under CULFB / Fibroblast Culture for Biochemical or Molecular Testing. An additional 3 to 4 weeks is required to culture fibroblasts before genetic testing can occur.

 

Specimen Type: Skin biopsy

Supplies: Fibroblast Biopsy Transport Media (T115)

Container/Tube: Sterile container with any standard cell culture media (eg, minimal essential media, RPMI 1640). The solution should be supplemented with 1% penicillin and streptomycin.

Specimen Volume: 4-mm punch

Specimen Stability Information: Refrigerated (preferred)/Ambient

Additional information: A separate culture charge will be assessed under CULFB / Fibroblast Culture for Biochemical or Molecular Testing. An additional 3 to 4 weeks is required to culture fibroblasts before genetic testing can occur.

 

Specimen Type: Blood spot

Supplies: Card - Blood Spot Collection (Filter Paper) (T493)

Container/Tube:

Preferred: Collection card (Whatman Protein Saver 903 Paper)

Acceptable: PerkinElmer 226 (formerly Ahlstrom 226) filter paper, or blood spot collection card

Specimen Volume: 2 to 5 Blood spots

Collection Instructions:

1. An alternative blood collection option for a patient older than 1 year is a fingerstick. For detailed instructions, see How to Collect Dried Blood Spot Samples.

2. Let blood dry on the filter paper at ambient temperature in a horizontal position for a minimum of 3 hours.

3. Do not expose specimen to heat or direct sunlight.

4. Do not stack wet specimens.

5. Keep specimen dry

Specimen Stability Information: Ambient (preferred)/Refrigerated

Additional Information:

1. Due to lower concentration of DNA yielded from blood spot, it is possible that additional specimen may be required to complete testing.

2. For collection instructions, see Blood Spot Collection Instructions

3. For collection instructions in Spanish, see Blood Spot Collection Card-Spanish Instructions (T777)

4. For collection instructions in Chinese, see Blood Spot Collection Card-Chinese Instructions (T800)

Special Instructions
Library of PDFs including pertinent information and forms related to the test

Forms

If not ordering electronically, complete, print, and send a Biochemical Genetics Test Request (T798) with the specimen.

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the testing laboratory. The minimum volume is sufficient for one attempt at testing.

Blood: 1 mL

Blood Spots: 5 punches, 3-mm diameter

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen Type Temperature Time Special Container
Varies Varies

Useful For
Suggests clinical disorders or settings where the test may be helpful

Confirmation of a diagnosis of Gaucher disease

 

Carrier screening in cases where there is a family history of Gaucher disease, but an affected individual is not available for testing or disease-causing alterations have not been identified

Genetics Test Information
Provides information that may help with selection of the correct genetic test or proper submission of the test request

Testing includes full gene sequencing of the GBA gene.

 

Risk alleles for Parkinson disease with no known beta-glucocerebrosidase enzyme reduction or Gaucher disease association will only be reported in patients over 18 years old unless otherwise requested.

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

For skin biopsy or cultured fibroblast specimens, fibroblast culture testing will be performed at an additional charge. If viable cells are not obtained, the client will be notified.

 

For more information see Newborn Screen Follow-up for Gaucher Disease.

 

If the patient has abnormal newborn screening results for Gaucher disease, refer to the appropriate American College of Medical Genetics and Genomics Newborn Screening ACT Sheet.(1)

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Gaucher disease is a relatively rare lysosomal storage disorder resulting from a deficiency of acid beta-glucocerebrosidase. Reduced or absent activity of this enzyme results in accumulation of its substrate in lysosomes, interfering with cell function. There are 3 major types of Gaucher disease: nonneuropathic (type 1), acute neuropathic (type 2), and subacute neuropathic (type 3). In addition, there are 2 rare presentations of Gaucher disease: a perinatal lethal form associated with skin abnormalities and nonimmune hydrops fetalis, and a cardiovascular form presenting with calcification of the aortic and mitral valves, mild splenomegaly, and corneal opacities. Gaucher disease demonstrates large clinical variability, even within families.

 

Type 1 accounts for over 95% of all cases of Gaucher disease and is the presentation commonly found among Ashkenazi Jewish patients. The carrier rate of Gaucher disease in the Ashkenazi Jewish population is 1:18. There is a broad spectrum of disease in type 1 Gaucher disease, with some patients exhibiting severe symptoms and others very mild disease. Type 1 disease does not involve nervous system dysfunction; patients may display anemia, low blood platelet levels, massively enlarged livers and spleens, lung infiltration, and extensive skeletal disease. Type 2 is characterized by early-onset neurologic disease with rapid progression to death by 2 to 4 years of age. Type 3 may have early onset of symptoms, but generally a slower disease progression than type 2.

 

Alterations in the GBA gene cause the clinical manifestations of Gaucher disease. Over 250 variants have been reported to date. The N370S and L444P alterations have the highest prevalence in most populations. N370S is associated with type 1 Gaucher disease, and individuals with at least 1 copy of this alteration do not develop the primary neurologic disease seen in types 2 and 3. Conversely, L444P is associated with neurologic disease.

 

Alterations in the GBA gene have also been reported to cause an increased risk for Parkinson disease. Alterations associated with Parkinson disease, but not Gaucher disease, are not routinely reported for patients under the age of 18, but are available upon request.

 

For carrier screening of the general population, the recommended test is GAUP / Gaucher Disease, Mutation Analysis, GBA, Varies, which tests for the 8 most common GBA alterations. For diagnostic testing (ie, potentially affected individuals), enzyme testing (GBAW / Beta-Glucosidase, Leukocytes) should be performed prior to variant analysis. In individuals with abnormal enzyme activity and 1 or no variants detected by a panel of common alterations, sequence analysis of the GBA gene should be utilized to detect private variants. Additionally, measurement of the glucopsychosine biomarker can aid in diagnosis and ongoing therapeutic monitoring (GPSY / Glucopsychosine, Blood Spot).

Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

An interpretive report will be provided.

Interpretation
Provides information to assist in interpretation of the test results

All detected alterations are evaluated according to American College of Medical Genetics and Genomics (ACMG) recommendations.(2) Variants are classified based on known, predicted, or possible pathogenicity and reported with interpretive comments detailing their potential or known significance.

Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

A small percentage of individuals who are carriers or have a diagnosis of Gaucher disease may have a variant that is not identified by this method (eg, large genomic deletions, promoter alterations). The absence of a variant, therefore, does not eliminate the possibility of positive carrier status or the diagnosis of Gaucher disease. For carrier testing, it is important to first document the presence of a GBA gene variant in an affected family member.

 

In some cases, DNA alterations of undetermined significance may be identified.

 

Rare alterations exist that could lead to false-negative or false-positive results. If results obtained do not match the clinical findings, additional testing should be considered.

 

Test results should be interpreted in the context of clinical findings, family history, and other laboratory data. Errors in the interpretation of results may occur if information given is inaccurate or incomplete.

Clinical Reference
Recommendations for in-depth reading of a clinical nature

1. Newborn Screening ACT Sheet [Decreased beta-glucocerebrosidase] Gaucher Disease. American College of Medical Genetics and Genomics; 2022. Revised March 2022. Accessed June 10, 2024. Available at www.acmg.net/PDFLibrary/Gaucher.pdf

2. Richards S, Aziz N, Bale S, et al: Standards and guidelines for the interpretation of sequence variants: a joint consensus recommendation of the American College of Medical Genetics and Genomics and the Association for Molecular Pathology. Genet Med. 2015 May;17(5):405-424

3. Guggenbuhl P, Grosbois B, Chales G: Gaucher disease. Joint Bone Spine. 2008 Mar;75(2):116-124

4. Hruska KS, LaMarca ME, Scott CR, Sidransky E: Gaucher disease: mutation and polymorphism spectrum in the glucocerebrosidase gene (GBA). Hum Mutat. 2008 May;29(5):567-583

5. O'Regan G, deSouza RM, Balestrino R, Schapira AH: Glucocerebrosidase mutations in Parkinson disease. J Parkinsons Dis. 2017;7(3):411-422

Method Description
Describes how the test is performed and provides a method-specific reference

Bidirectional sequence analysis is performed to test for the presence of a variant in all coding regions and intron/exon boundaries of the GBA gene.(Unpublished Mayo method)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information

No

Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Varies

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

14 to 20 days

Performing Laboratory Location
Indicates the location of the laboratory that performs the test

Rochester

Fees :
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.

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Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

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.

CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.

81479-Unlisted molecular pathology procedure code

88233-Tissue culture, skin, or solid tissue biopsy (if appropriate)

88240-Cryopreservation (if appropriate)

LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.

Test Id Test Order Name Order LOINC Value
GBAZ Gaucher Disease, Full Gene Analysis 94230-0
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.
53477 Result Summary 50397-9
53478 Result 82939-0
53479 Interpretation 69047-9
53480 Additional Information 48767-8
53481 Specimen 31208-2
53482 Source 31208-2
53483 Released By 18771-6

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports