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HelpTest Code SMNCS Spinal Muscular Atrophy Carrier Screening, Deletion/Duplication Analysis, Varies
Additional Testing Requirements
Shipping Instructions
Specimen preferred to arrive within 96 hours of collection.
Specimen Required
Patient Preparation: A previous bone marrow transplant from an allogenic donor will interfere with testing. Call Mayo Clinic Laboratories for instructions for testing patients who have received a bone marrow transplant.
Submit only 1 of the following specimens:
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
Additional Information: To ensure minimum volume and concentration of DNA is met, the preferred volume of blood must be submitted. Testing may be canceled if DNA requirements are inadequate.
Specimen Type: Blood spot
Supplies: Card-Blood Spot Collection (Filter paper) T493
Container/Tube:
Preferred: Collection card (Whatman Protein Saver 903 Paper)
Acceptable: PerkinElmer 226 (formerly Ahlstrom 226) filter paper or blood spot collection card
Specimen Volume: 5 Blood spots
Collection Instructions:
1. An alternative blood collection option for a patient older than 1 year is a fingerstick. For detailed instructions, see How to Collect Dried Blood Spot Samples.
2. Let blood dry on the filter paper at ambient temperature in a horizontal position for a minimum of 3 hours.
3. Do not expose specimen to heat or direct sunlight.
4. Do not stack wet specimens.
5. Keep specimen dry
Specimen Stability Information: Ambient (preferred)/Refrigerated
Additional Information:
1. Due to lower concentration of DNA yielded from blood spot, it is possible that additional specimen may be required to complete testing.
2. For collection instructions, see Blood Spot Collection Instructions
3. For collection instructions in Spanish, see Blood Spot Collection Card-Spanish Instructions (T777)
4. For collection instructions in Chinese, see Blood Spot Collection Card-Chinese Instructions (T800)
Specimen Type: Cultured fibroblasts
Container/Tube: T-75 or T-25 flask
Specimen Volume: 1 full T-75 or 2 full T-25 flasks
Specimen Stability Information: Ambient (preferred)/Refrigerated <24 hours
Additional Information: A separate culture charge will be assessed under CULFB / Fibroblast Culture for Biochemical or Molecular Testing. An additional 3 to 4 weeks is required to culture fibroblasts before genetic testing can occur.
Specimen Type: Skin biopsy
Supplies: Fibroblast Biopsy Transport Media (T115)
Container/Tube: Sterile container with any standard cell culture media (eg, minimal essential media, RPMI 1640). The solution should be supplemented with 1% penicillin and streptomycin. Tubes can be supplied upon request (Eagle's minimum essential medium with 1% penicillin and streptomycin [T115]).
Specimen Volume: 4-mm punch
Specimen Stability Information: Refrigerated (preferred)/Ambient
Additional Information: A separate culture charge will be assessed under CULFB / Fibroblast Culture for Biochemical or Molecular Testing. An additional 3 to 4 weeks is required to culture fibroblasts before genetic testing can occur.
Specimen Type: Tissue biopsy
Supplies: Muscle Biopsy Kit (T541)
Collection Instructions: Prepare and transport specimen per instructions in Muscle Biopsy Specimen Preparation Instructions.
Additional Information: Muscle Biopsy Shipping Kits (T541) are available.
Specimen Volume: 10-80 mg
Specimen Stability Information: Frozen (preferred)/Ambient/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 in Special Instructions:
-Informed Consent for Genetic Testing (T576)
-Informed Consent for Genetic Testing-Spanish (T826)
2. Molecular Genetics: Congenital Inherited Diseases Patient Information (T521) in Special Instructions
Useful For
General population carrier screening for spinal muscular atrophy (SMA)
Carrier screening for reproductive partners of known SMA carriers
Carrier screening for parents of a child with a known deletion of the survival motor neuron 1 gene (SMN1) or other family history of SMA
Reflex Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| CULFB | Fibroblast Culture for Genetic Test | Yes | No |
Testing Algorithm
For skin biopsy or cultured fibroblast specimens, fibroblast culture testing will be performed at an additional charge. If viable cells are not obtained, the client will be notified.
Special Instructions
- Molecular Genetics: Congenital Inherited Diseases Patient Information
- Muscle Biopsy Specimen Preparation Instructions
- Informed Consent for Genetic Testing
- Blood Spot Collection Card-Spanish Instructions
- Blood Spot Collection Card-Chinese Instructions
- Informed Consent for Genetic Testing (Spanish)
- Blood Spot Collection Instructions
Method Name
Dosage Analysis by Digital Droplet Polymerase Chain Reaction (ddPCR)
Reporting Name
SMA Carrier by Del/DupSpecimen Type
VariesSpecimen Minimum Volume
Blood: 1 mL
Tissue Biopsy: 200 mg
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Varies | Varies | ||
Reference Values
An interpretive report will be provided.
Interpretation
An interpretive report will be provided.
Clinical Reference
1. D'Amico A, Mercuri E, Tiziano FD, Bertini E: Spinal muscular atrophy. Orphanet J Rare Dis 2011;6:71
2. Hendrickson BC, Donohoe C, Akmaev VR, et al: Differences in SMN1 allele frequencies among ethnic groups within North America. J Med Genet 2009;46:641-644
3. Carre A, Empey C: Review of Spinal Muscular Atrophy (SMA) for Prenatal and Pediatric Genetic Counselors. 2016;25:32-43
4. Committee on Genetics: Committee Opinion No. 690: Carrier Screening in the Age of Genomic Medicine. Obstet Gynecol 2017;129:e35-e40
5. Committee on Genetics: Committee Opinion No. 691: Carrier Screening for Genetic Conditions. Obstet Gynecol March 2017;129;e41-e55
6. Luo M, Liu L, Peter I, et al: An Ashkenazi Jewish SMN1 haplotype specific to duplication alleles improves pan-ethnic carrier screening for spinal muscular atrophy. Genet Med 2014;16:149-156
7. Prior TW, Nagan N: Spinal muscular atrophy: overview of molecular diagnostic approaches. Curr Protoc Hum Genet 2016;1:88 unit 9.27
8. Prior TW, Nagan N, Sugarman EA, et al: Technical standards and guidelines for spinal muscular atrophy testing. Genet Med 2011;13:686-694
Day(s) Performed
Varies
Report Available
5 to 10 daysPerforming 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
81329
88233 (if appropriate)
88240 (if appropriate)
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| SMNCS | SMA Carrier by Del/Dup | 49857-6 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 113445 | Result Summary | 50397-9 |
| 113446 | Result | 49857-6 |
| 113447 | Interpretation | 69047-9 |
| 113448 | Additional Information | 48767-8 |
| 113449 | Specimen | 31208-2 |
| 113450 | Source | 31208-2 |
| 113451 | Released By | 18771-6 |