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Test Code SCN5A Brugada Syndrome, SCN5A Full Gene Analysis, Varies


Ordering Guidance


This single gene test is intended for genetic screening for and diagnosis of Brugada syndrome.

For comprehensive inherited cardiac arrhythmia genetic testing, order CARGG / Comprehensive Arrhythmia Gene Panel, Varies.

 

Testing for SCN5A as part of a customized panel is available. For more information see CGPH / Custom Gene Panel, Hereditary, Next-Generation Sequencing, Varies.

 

Targeted testing for familial variants (also called site-specific or known mutations testing) is available for variants identified in the SCN5A gene. See FMTT / Familial Variant, Targeted Testing, Varies. To obtain more information about this testing option, call 800-533-1710.



Shipping Instructions


Specimen preferred to arrive within 96 hours of collection.



Necessary Information


Prior Authorization is available, but not required, for this test. If proceeding with the prior authorization process, submit the required form with the specimen.



Specimen Required


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.

 

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 whole blood specimen in original tube. Do not aliquot.

Specimen Stability Information: Ambient (preferred)/Refrigerated


Forms

1. New York Clients-Informed consent is required. Document on the request form or electronic order that a copy is on file.

The following documents are available:

-Informed Consent for Genetic Testing (T576)

-Informed Consent for Genetic Testing (Spanish) (T826)

2. Hereditary Cardiomyopathies and Arrhythmias: Patient Information (T725)

3. If not ordering electronically, complete, print, and send a Cardiovascular Test Request Form (T724) with the specimen.

4. Brugada Syndrome Test (SCN5A) Prior Authorization Ordering Instructions

Secondary ID

617449

Useful For

Providing a genetic evaluation for patients with a personal or family history suggestive of Brugada syndrome

 

Establishing a diagnosis of Brugada syndrome

Method Name

Sequence Capture and Targeted Next-Generation Sequencing followed by Polymerase Chain Reaction (PCR) and Sanger Sequencing.

Reporting Name

Brugada Syndrome, SCN5A Full Gene

Specimen Type

Varies

Specimen Minimum Volume

1 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Varies Varies

Reject Due To

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

Clinical Information

Brugada syndrome (BrS) is a genetic cardiac disorder characterized by ST segment elevation in leads V1-V2 on electrocardiography (ECG) occurring spontaneously or after administration of sodium-channel blockers.(1) BrS leads to a high risk for ventricular arrhythmias, which can result in sudden cardiac arrest and sudden cardiac death including sudden unexpected nocturnal death syndrome  and sudden infant death syndrome.(2) The diagnosis of BrS is established based on the characteristic ECG abnormality along with personal and family health history and requires exclusion of other causes including cardiac structural abnormalities, medications, and electrolyte imbalances.(2)

 

BrS has an estimated prevalence of 1:2000 to 1:5000.(1) Currently, BrS is definitively associated with gain-of-function variants in the SCN5A gene(3) and the condition follows an autosomal dominant pattern of inheritance. Approximately 20% of individuals meeting clinical diagnostic criteria for BrS are found to carry a causative variant in the SCN5A gene.(3) While variants in other genes have been reported in association with BrS, current evidence is not sufficient to define the role of these genes in BrS.(3)

Reference Values

An interpretive report will be provided.

Interpretation

All detected variants are evaluated according to American College of Medical Genetics and Genomics recommendations.(4) Variants are classified based on known, predicted, or possible pathogenicity and reported with interpretive comments detailing their potential or known significance.

Method Description

Next generation sequencing (NGS) and/or Sanger sequencing are performed to test for the presence of variants in coding regions and intron/exon boundaries of SCN5A, as well as some other regions that have known disease-causing variants. The human genome reference GRCh37/hg19 build was used for sequence read alignment. At least 99% of the bases are covered at a read depth over 30X. Sensitivity is estimated at above 99% for single nucleotide variants, above 94% for deletion-insertions (delins) less than 40 base pairs (bp), above 95% for deletions up to 75 bp and insertions up to 47 bp. NGS and/or a polymerase chain reaction-based quantitative method is performed to test for the presence of deletions and duplications in SCN5A.

 

There may be regions of genes that cannot be effectively evaluated by sequencing or deletion and duplication analysis as a result of technical limitations of the assay, including regions of homology, high guanine-cytosine (GC) content, and repetitive sequences.(Unpublished Mayo method)

 

The reference transcript for the SCN5A gene is NM_198056.2. Reference transcript numbers may be updated due to transcript re-versioning. Always refer to the final patient report for gene transcript information referenced at the time of testing. Confirmation of select reportable variants may be performed by alternate methodologies based on internal laboratory criteria.

Day(s) Performed

Varies

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

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

81407

LOINC Code Information

Test ID Test Order Name Order LOINC Value
SCN5A Brugada Syndrome, SCN5A Full Gene 55139-0

 

Result ID Test Result Name Result LOINC Value
617450 Test Description 62364-5
617451 Specimen 31208-2
617452 Source 31208-2
617453 Result Summary 50397-9
617454 Result 82939-0
617455 Interpretation 69047-9
617456 Additional Results 82939-0
617457 Resources 99622-3
617458 Additional Information 48767-8
617459 Method 85069-3
617460 Genes Analyzed 48018-6
617461 Disclaimer 62364-5
617462 Released By 18771-6

Prior Authorization

Insurance preauthorization is available for this testing; forms are available.

 

Patient financial assistance may be available to those who qualify. Patients who receive a bill from Mayo Clinic Laboratories will receive information on eligibility and how to apply.