Spinal Muscular Atrophy Carrier Screening, Deletion/Duplication Analysis, Varies
Use
This test is useful for carrier screening for spinal muscular atrophy (SMA) in the general population and for reproductive partners of known SMA carriers. It is also useful for carrier screening for parents of a child with a known deletion of the SMN1 gene or other family history of SMA. SMA is an autosomal recessive disorder characterized by motor neuron degeneration, muscular atrophy, and paralysis. The severity of SMA is associated with the number of copies of the SMN2 gene present, with more copies associated with a milder phenotype.
Special Instructions
Not provided.
Limitations
Point mutations are undetectable by this assay and it cannot definitively discriminate between two copies of SMN1 on the same chromosome versus on separate chromosomes. Rare polymorphisms could lead to false-negative or false-positive results. If results do not match clinical findings, additional testing should be considered. Interpretation may be affected by improper specimen collection, handling, or test selection.
New York Approved
Methodology
PCR-based (ddPCR)
Biomarkers
LOINC Codes
- 49857-6 - SMN1+SMN2 gene Mut Anl Bld/T
- 50397-9 - Mol dx interp Bld/T Ql
- 49857-6 - SMN1+SMN2 gene Mut Anl Bld/T
- 69047-9 - Geneticist review
- 48767-8 - Annotation comment Imp
- 31208-2 - Specimen source
- 18771-6 - Provider signing name
Result Turnaround Time
5-10 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
3 mL
Minimum Volume
Not provided
Container
Lavender top (EDTA) or yellow top (ACD)
Collection Instructions
Invert several times to mix blood. Send in original tube. Do not aliquot. Whole blood collected postnatal from an umbilical cord is also acceptable.
Patient Preparation
A previous hematopoietic stem cell transplant from an allogenic donor will interfere with testing.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 4 days |
| Refrigerated | 4 days |
| Frozen | 4 days |