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Test Code C9ORF C9orf72 Hexanucleotide Repeat, Molecular Analysis

Useful For

Molecular confirmation of clinically suspected cases of c9FTD/ALS, frontotemporal dementia (FTD), or amyotrophic lateral sclerosis (ALS)

 

Presymptomatic testing for individuals with a family history of c9FTD/ALS and a documented expansion in the C9orf72 gene

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
C9FU C9orf72, Follow Up Analysis No No

Method Name

Polymerase Chain Reaction (PCR)

Reporting Name

C9orf72, Molecular Analysis

Specimen Type

Varies


Shipping Instructions


Specimen preferred to arrive within 96 hours of collection.



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 

Reference Values

Normal alleles: <20 GGGGCC repeats

Intermediate alleles: 20-29 GGGGCC repeats

Full penetrance: >29* GGGGCC repeats

 

*Alleles greater than 30 repeats are outside the reportable range for this assay and are detected using the companion Southern blot assay. There is not enough information at this time to determine if 30 repeats is the cutoff for pathogenicity.

 

An interpretive report will be provided.

Day(s) and Time(s) Performed

Tuesday; 10 a.m.

Performing Laboratory

Mayo Medical Laboratories in Rochester

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

 

Reflex Tests

C9orf72, Follow Up Analysis

81479-Unlisted Molecular Pathology procedure

LOINC Code Information

Test ID Test Order Name Order LOINC Value
C9ORF C9orf72, Molecular Analysis In Process

 

Result ID Test Result Name Result LOINC Value
52852 Result Summary 50397-9
52853 Result 77635-1
52854 Interpretation 69047-9
52855 Reason for Referral 42349-1
52856 Specimen 31208-2
55158 Method 49549-9
52857 Source 31208-2
52858 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