Spinal muscular atrophy (SMA)-13550

Test info

  
Spinal muscular atrophy (SMA)
  
13550
  
LAB13550
  
SMA
  
Dubowitz disease (SMA type II)
Kugelberg-Welander disease (SMA type III)
Prenatal SMA
SMA
Werdnig-Hoffman disease (SMA type I)
SMA types I, II, III
SMN1 copy number analysis
Spinal Muscular Atrophy (SMA) Carrier Testing
  
This test includes the following gene: SMN1
  
  • Diagnostic testing for individuals suspected of having spinal muscular atrophy.
  • Carrier testing for individuals in the general population, or individuals with a family history of SMA, or couples who are planning a pregnancy or who are already pregnant.
  • Prenatal diagnosis for at-risk pregnancies, when both parents are carriers or when severe joint contractures are found on fetal ultrasound.
  

Technologies used do not detect germline mosaicism and do not rule out the presence of large chromosomal aberrations including rearrangements and gene fusions, or variants in regions or genes not included in this test, or possible inter/intragenic interactions between variants or repeat expansions.

Variant classification and/or interpretation may change over time if more information becomes available. False positive or false negative results may occur for reasons that include: rare genetic variants, sex chromosome abnormalities, pseudogene interference, blood transfusions, bone marrow transplantation, somatic or tissue-specific mosaicism, mislabeled samples or erroneous representation of family relationships.

This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration.

Specimen

  
ACD-A whole blood
  
  
8.5 mL
  
3 mL
  
  • In some circumstances, specimens from other family members may be required
  • Immediately following collection, mix by inverting 8 - 10 times to prevent clotting
  

Yellow ACD-A

  
EDTA whole blood
  
  

Immediately following collection, mix by inverting 8 - 10 times to prevent clotting

  

Lavender (EDTA), 10mL

  

Ambient (preferred) - 4 days

Refrigerated - 4 days

  
  • Frozen specimen
  • Hemolysis
  • Quantity not sufficient for analysis
  • Improper container
  • Blood specimens more than four days post draw
  • Yellow-top (ACD-B) tubes are not acceptable

Performance

  
LabCorp (481630): R-LC
  
Mo - Sa
  
8 - 14 days
  

Copy number assessment of SMN1 exon 7 by quantitative polymerase chain reaction (qPCR); reflex testing to SMN2 copy number analysis is performed for individuals with 0 copies of SMN1. For carrier screening, when two copies of SMN1 are detected, allelic discrimination qPCR targeting c.*3+80T>G in SMN1 is performed. The presence or absence of c.*3+80T>G correlates with an increased or decreased risk, respectively, of being a silent carrier (2+0).

Clinical and Interpretive info

  

An interpretive report will be provided

Billing

  
This test may require preauthorization from the insurance provider. Check the payer guidelines and, if needed, obtain the pre-authorization prior to sample collection.
  
81329
  
Yes
  
Result UNLOINC
  

Medical necessity

Hospital clients submitting a request for this assay on an outpatient with Medicare should complete and submit a Molecular Medical billing request form along with the sample.

  • Complete and submit the form to notify us of the need for Allina Health Laboratory to bill insurance for Molecular testing performed
  • All information requested is required in order for your request to be completed

Molecular Medicare billing request

Tracking

  
04/11/2019
  
09/20/2023
  
12/21/2023