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Test Code BM6059 Spinal Muscular Atrophy (SMN1 & SMN2) Deletion Analysis

Additional Codes

EPIC: order Miscellaneous Genetics Lab Test (LAB3953)

Performing Laboratory

St. Louis Children's Hospital Sendout to Baylor College of Medicine - Medical Genetics Laboratories

Specimen Requirements

Specimen Type: Blood

Patient Preparation: None

Container/Tube        

Preferred/Acceptable:  Lavender-top (EDTA) Vacutainer®.
Collection Volume: 3.0-5.0 mL (minimum 3.0 mL)

Special Instructions:

  •  Immediately invert tube gently 8-10 times after collection to ensure proper mixing of blood and anticoagulant (this will avoid specimen clotting).
  • Send a completed "Baylor Molecular Diagnostics Requisition Form" with the specimen. Please NOTE: "indication for Study" on the requisition MUST be completed or the sample may be discarded or cancelled/returned by BCM-MGL.

 

Sample Rejection

For patients over the age of 10 yrs, if sample submitted without a symptomatic indication or with no indication provided, test may be cancelled by BCM_MLG

Mislabeled or unlabeled specimens.

Logistics

Test Availability:  Daily

Cut-off time: None

Days set up by performing lab: Monday-Friday

Turnaround Time: 14 days

Reference Values

Reference Interval: Interpretive report will be provided

Critical Value: None established

Methodology

Multiplex Ligation-dependent Probe amplification (MLPA)

Limitations

  • THe SMA assay performed at BCM-Medical Genetics Laboratories is for diagnostic evaluation of symptomatic individuals and does not detect carriers for SMA. 
  • Less commonly, pathogenic sequence variants of SMN1 are disease-causing and will not be detected by this assay.

Additional Information

FOR SLCH CORE LABORATORY USE ONLY

Lab Processing Instructions: DO NOT SPIN. Send in orginal vacutainer

Processed volume: 3.0-5.0 mL (minimum 3.0 mL) whole blood

Transport Temperature: Ambient, in insulated container 
Analyte Stability: 

Specimen Type    Temperature Time
Whole Blood   Ambient (preferred)   48 hours   
  Refrigerated    5 days
  Frozen   UNACCEPTABLE   

Note: 

  1. Specimens should be shipped at room temperature (or with a cool pack if sent during warmer months) by overnight express. Specimen may be shipped Friday for Saturday deliver as long as shipment is marked for Saturday delivery. Specimen must arrive at Baylor lab within 48 hours of collecion.
  2. Send the completed "Baylor Molecular Diagnostics Requisition Form" with specimen. NOTE: "Indication for Study" section on form MUST be completed or sample may be discarded or cancelled and returned y BCM-MGL
  3. DO NOT transfer blood to other containers

Test Classification and CPT Code

81329

LOINC

NA

Last Reviewed

08/2025