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Test ID: SEPTZ SEPT9 Gene, Mutation Screen

Useful For

Confirmation of a diagnosis of hereditary neuralgic amyotrophy

Method Name

Polymerase Chain Reaction (PCR) Followed by DNA Sequence Analysis

Reporting Name

SEPT9 Gene, Mutation Screen

Specimen Type

Varies


Shipping Instructions


Specimen preferred to arrive within 96 hours of draw.



Specimen Required


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 Minimum Volume

1 mL

Specimen Stability Information

Specimen Type Temperature Time
Varies Ambient (preferred)
  Frozen 
  Refrigerated 

Clinical Information

Hereditary neuralgic amyotrophy (HNA) is an autosomal dominant disorder characterized by periods of severe pain involving the brachial plexus followed by muscle atrophy and weakness. These recurrent episodes can also be accompanied by decreased sensation and paresthesias. Individuals with this disease are generally symptom-free between pain attacks, though many experience lingering effects with repeated attacks. The pain episodes are frequently triggered by physical, emotional, or immunological stress. Less commonly, affected individuals can exhibit nonneurological features including short stature, skin folds, hypotelorism, and cleft palate.

 

Mutations in the SEPT9 gene cause the clinical manifestations of HNA. There are 3 common mutations that have been reported in affected individuals: c.-134G->C, p.R88W, and p.S93F. Additionally, a common exonic duplication attributed to the founder effect has been identified in North American HNA families. Other private duplications of varying sizes have also been identified in affected individuals. SEPT9 is currently the only known gene associated with HNA, although approximately 15% of HNA families do not show linkage to this gene.

Reference Values

An interpretive report will be provided.

Interpretation

All detected alterations are evaluated according to American College of Medical Genetics recommendations.(1) Variants are classified based on known, predicted, or possible pathogenicity and reported with interpretive comments detailing their potential or known significance.

Clinical Reference

1. 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

2. Hannibal MC, Ruzzo EK, Miller LR, et al: SEPT9 gene sequencing analysis reveals recurrent mutations in hereditary neuralgic amyotrophy. Neurology 2009 May 19;72(20):1755-1759

3. Landsverk ML, Ruzzo EK, Mefford HC, et al: Duplication within the SEPT9 gene associated with a founder effect in North American families with hereditary neuralgic amyotrophy. Hum Mol Genet 2009 Apr 1;18(7):1200-1208

4. Collie AM, Landsverk ML, Ruzzo E, et al: Non-recurrent SEPT9 duplications cause hereditary neuralgic amyotrophy. J Med Genet 2010 Sep;47(9):601-607

Day(s) and Time(s) Performed

Performed weekly, Varies

Analytic Time

14 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 U.S. Food and Drug Administration.

CPT Code Information

81479-Unlisted molecular pathology procedure

LOINC Code Information

Test ID Test Order Name Order LOINC Value
SEPTZ SEPT9 Gene, Mutation Screen In Process

 

Result ID Test Result Name Result LOINC Value
53547 Result Summary 50397-9
53548 Result In Process
53549 Interpretation In Process
53550 Additional Information 48767-8
53551 Specimen In Process
53552 Source 31208-2
53553 Released By No LOINC Needed

Forms

1. New York Clients-Informed consent is required. Please document on the request form or electronic order that a copy is on file. An Informed Consent for Genetic Testing (T576) is available in Special Instructions.

2. Molecular Genetics: Neurology Patient Information in Special Instructions

3. If not ordering electronically, complete, print, and send a Neurology Specialty Testing Client Test Request (T732) with the specimen (http://www.mayomedicallaboratories.com/it-mmfiles/neurology-request-form.pdf

Mayo Medical Laboratories | Genetics and Pharmacogenomics Catalog Additional Information:

mml-inherited-molecular