Test Overview
Test Methodology

MLPA probes hybridize to target regions of SMN1 and SMN2 genes and are amplified by multiplex PCR. The amplification products are analyzed by capillary electrophoresis and SMN1 and SMN2 copy numbers are generated.

Test Usage

Detection of the copy number (deletions/duplications) of the SMN1 and SMN2 genes in patients with a clinical diagnosis of Spinal Muscular Atrophy.

Reference Range *

Interpretive report provided.

*Reference ranges may change over time. Please refer to the original patient report when evaluating results.

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Test Limitations

This assay will not detect point mutations or frame-shift mutations in SMN1 or SMN2 genes.

Test Details
Days Set Up
Monday - Friday
Soft Order Code
SMNSC
MiChart Code
SMN1, SMN2 Deletion/Duplication Analysis (non-blood)
Synonyms
    Laboratory
    MMGL
    Section
    MMGL Molecular Genetics
    Specimen Requirements
    Collection

    Cheek swab kit (Oracollect OCD-100), follow collection instructions.
    Saliva kit (Oragene OGD-510), follow collection instructions.

    Collection Instructions

    This test is not currently orderable for MLABS clients.

    Normal Volume

    2 Cheek Swabs
    1 Saliva Kit

    Minimum Volume

    2 Cheek Swabs
    1 Saliva Kit

    Storage Temperature
    2-36°C for cheek swab or saliva kit
    Additional Information

    Spinal Muscular Atrophy (SMA) is an autosomal recessive neuromuscular disorder. SMN1 and SMN2 are two highly-similar genes that have a critical role in defining SMA. SMN2 is much less efficient in making the SMN protein; therefore it is the SMN1 gene which is the determinant factor in SMA. Most patients with SMA are homozygous for a deletion or gene conversion of SMN1. The presence of multiple copies of SMN2 in patients homozygous for a deletion or gene conversion of SNM1 can modify the phenotype and lead to less severe disease.

    Most insurance carriers require prior authorization for genetic testing. Testing will not begin until insurance prior authorization is received by the laboratory or it is confirmed that prior authorization is not required. The ordering health care provider can obtain the prior authorization or request the laboratory to submit it. To obtain BCN prior authorization call Joint Venture Hospital Laboratories (JVHL) at 800-445-4979; for all other insurances, contact the plan directly. By ordering this test the clinician acknowledges that informed consent, https://mlabs.umich.edu/sites/default/files/2023-04/file/germline-conse…, has been obtained from the patient as required by applicable state or federal laws and the ordering clinician has authorization from the patient permitting MLabs to report the test results to the ordering clinician. Test includes medical geneticist interpretation of results billed as a separate additional charge. This test is not available without interpretation.

    Billing
    CPT Code
    81329
    Fee Code
    DA157
    Pro Fee CPT
    G0452-26
    NY State Approved
    No