Test Details
Methodology
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).
Result Turnaround Time
8 - 14 days (In some cases, additional time may be required for confirmatory or reflex tests.)
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Test Includes
This test includes the following gene: SMN1.
Use
This test is used for carrier screening for spinal muscular atrophy and diagnostic testing for individuals suspected of having spinal muscular atrophy.
Special Instructions
To test fetal specimens, including cord blood, order Spinal Muscular Atrophy (SMA), Fetal Analysis [481651].
Test orders must include an attestation that the provider has the patient's informed consent for genetic testing.
Limitations
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.
References
Specimen Requirements
Specimen
Whole blood or PurFlock buccal swab kit or Oragene Dx 500 saliva kit
Volume
8.5 mL whole blood or PurFlock buccal swab kit or Oragene Dx saliva kit
Minimum Volume
3 mL whole blood or PurFlock buccal swab kit or Oragene Dx saliva kit
Container
Yellow-top (ACD-A) tube or lavender-top (EDTA) tube or PurFlock buccal swab kit or Oragene Dx 500 saliva collection kit
Collection Instructions
Standard phlebotomy; follow PurFlock buccal swab kit or Oragene Dx 500 saliva kit collection instructions. Do not eat, drink, smoke, or chew gum 30 minutes prior to collection.
Stability Requirements
Whole blood: 4 days at room temperature or 4°C
Buccal: 60 days at room temperature
Saliva: 60 days at room temperature
Storage Instructions
Maintain specimen at room temperature or refrigerate at 4°C. Do not freeze.
Causes for Rejection
Frozen or hemolyzed specimen; quantity not sufficient for analysis; improper container or blood specimens more than four days post draw
LOINC® Map
| Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
|---|---|---|---|---|---|---|
| 481630 | Spinal Muscular Atrophy (SMA) | 481608 | Ethnicity | 42784-9 | ||
| 481630 | Spinal Muscular Atrophy (SMA) | 481609 | Specimen Type | 31208-2 | ||
| 481630 | Spinal Muscular Atrophy (SMA) | 481610 | Genetic Counselor | 89993-0 | ||
| 481630 | Spinal Muscular Atrophy (SMA) | 481611 | Indication | 42349-1 | ||
| 481630 | Spinal Muscular Atrophy (SMA) | 481612 | Result: | 41053-0 | ||
| 481630 | Spinal Muscular Atrophy (SMA) | 482025 | SMN2 Copy Number Reflex | 54449-7 | ||
| 481630 | Spinal Muscular Atrophy (SMA) | 481613 | Interpretation | 53039-4 | ||
| 481630 | Spinal Muscular Atrophy (SMA) | 481614 | General Comments | 8262-8 | ||
| 481630 | Spinal Muscular Atrophy (SMA) | 481621 | Recommendations | 62385-0 | ||
| 481630 | Spinal Muscular Atrophy (SMA) | 481622 | Additional ClinicalInformation | 55752-0 | ||
| 481630 | Spinal Muscular Atrophy (SMA) | 481623 | Comments | 8251-1 | ||
| 481630 | Spinal Muscular Atrophy (SMA) | 481624 | Methods/Limitations | 49549-9 | ||
| 481630 | Spinal Muscular Atrophy (SMA) | 481626 | References | 75608-0 | ||
| 481630 | Spinal Muscular Atrophy (SMA) | 481627 | Director Review/Release | 72486-4 | ||
| 481630 | Spinal Muscular Atrophy (SMA) | 481628 | 51969-4 | |||
| Order Code | 481630 | |||||
| Order Code Name | Spinal Muscular Atrophy (SMA) | |||||
| Order Loinc | ||||||
| Result Code | 481608 | |||||
| Result Code Name | Ethnicity | |||||
| UofM | ||||||
| Result LOINC | 42784-9 | |||||
| Order Code | 481630 | |||||
| Order Code Name | Spinal Muscular Atrophy (SMA) | |||||
| Order Loinc | ||||||
| Result Code | 481609 | |||||
| Result Code Name | Specimen Type | |||||
| UofM | ||||||
| Result LOINC | 31208-2 | |||||
| Order Code | 481630 | |||||
| Order Code Name | Spinal Muscular Atrophy (SMA) | |||||
| Order Loinc | ||||||
| Result Code | 481610 | |||||
| Result Code Name | Genetic Counselor | |||||
| UofM | ||||||
| Result LOINC | 89993-0 | |||||
| Order Code | 481630 | |||||
| Order Code Name | Spinal Muscular Atrophy (SMA) | |||||
| Order Loinc | ||||||
| Result Code | 481611 | |||||
| Result Code Name | Indication | |||||
| UofM | ||||||
| Result LOINC | 42349-1 | |||||
| Order Code | 481630 | |||||
| Order Code Name | Spinal Muscular Atrophy (SMA) | |||||
| Order Loinc | ||||||
| Result Code | 481612 | |||||
| Result Code Name | Result: | |||||
| UofM | ||||||
| Result LOINC | 41053-0 | |||||
| Order Code | 481630 | |||||
| Order Code Name | Spinal Muscular Atrophy (SMA) | |||||
| Order Loinc | ||||||
| Result Code | 482025 | |||||
| Result Code Name | SMN2 Copy Number Reflex | |||||
| UofM | ||||||
| Result LOINC | 54449-7 | |||||
| Order Code | 481630 | |||||
| Order Code Name | Spinal Muscular Atrophy (SMA) | |||||
| Order Loinc | ||||||
| Result Code | 481613 | |||||
| Result Code Name | Interpretation | |||||
| UofM | ||||||
| Result LOINC | 53039-4 | |||||
| Order Code | 481630 | |||||
| Order Code Name | Spinal Muscular Atrophy (SMA) | |||||
| Order Loinc | ||||||
| Result Code | 481614 | |||||
| Result Code Name | General Comments | |||||
| UofM | ||||||
| Result LOINC | 8262-8 | |||||
| Order Code | 481630 | |||||
| Order Code Name | Spinal Muscular Atrophy (SMA) | |||||
| Order Loinc | ||||||
| Result Code | 481621 | |||||
| Result Code Name | Recommendations | |||||
| UofM | ||||||
| Result LOINC | 62385-0 | |||||
| Order Code | 481630 | |||||
| Order Code Name | Spinal Muscular Atrophy (SMA) | |||||
| Order Loinc | ||||||
| Result Code | 481622 | |||||
| Result Code Name | Additional ClinicalInformation | |||||
| UofM | ||||||
| Result LOINC | 55752-0 | |||||
| Order Code | 481630 | |||||
| Order Code Name | Spinal Muscular Atrophy (SMA) | |||||
| Order Loinc | ||||||
| Result Code | 481623 | |||||
| Result Code Name | Comments | |||||
| UofM | ||||||
| Result LOINC | 8251-1 | |||||
| Order Code | 481630 | |||||
| Order Code Name | Spinal Muscular Atrophy (SMA) | |||||
| Order Loinc | ||||||
| Result Code | 481624 | |||||
| Result Code Name | Methods/Limitations | |||||
| UofM | ||||||
| Result LOINC | 49549-9 | |||||
| Order Code | 481630 | |||||
| Order Code Name | Spinal Muscular Atrophy (SMA) | |||||
| Order Loinc | ||||||
| Result Code | 481626 | |||||
| Result Code Name | References | |||||
| UofM | ||||||
| Result LOINC | 75608-0 | |||||
| Order Code | 481630 | |||||
| Order Code Name | Spinal Muscular Atrophy (SMA) | |||||
| Order Loinc | ||||||
| Result Code | 481627 | |||||
| Result Code Name | Director Review/Release | |||||
| UofM | ||||||
| Result LOINC | 72486-4 | |||||
| Order Code | 481630 | |||||
| Order Code Name | Spinal Muscular Atrophy (SMA) | |||||
| Order Loinc | ||||||
| Result Code | 481628 | |||||
| Result Code Name | ||||||
| UofM | ||||||
| Result LOINC | 51969-4 |