Spinal muscular atrophy (SMA)-13550
Test info
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
- 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
- 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
Immediately following collection, mix by inverting 8 - 10 times to prevent clotting
Lavender (EDTA), 10mL
Molecular Medicare Billing Request
Hospital clients submitting a request for this assay on an outpatient with Medicare should complete and submit a Molecular Medicare billing request form to notify us of the need for Allina Health Laboratory to bill insurance.
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
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
Hospital clients submitting a request for this assay on an outpatient with Medicare should complete and submit a Molecular Medicare billing request form to notify us of the need for Allina Health Laboratory to bill insurance.