Spinal Muscular Atrophy (SMA)

Also known as: SMA testing, SMA types I, II, III, SMN1 copy number analysis

Clinical Use

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

Not provided.

Limitations

This test does not detect germline mosaicism and cannot identify large chromosomal aberrations such as rearrangements and gene fusions. It does not evaluate variants in genes not included in the test nor does it consider inter/intragenic interactions or repeat expansions. Results may be impacted by rare genetic variants, pseudogene interference, or identity issues such as mislabeled samples.

Test Details

Methodology

PCR-based (qPCR)

Biomarkers

SMN1

Gene

Copy Number

Mutation • Categorical (e.g., Positive / Negative / Indeterminate)

LOINC Codes

Result Codes

42784-9 - Ethnic Background Stated
31208-2 - Specimen source
89993-0 - Clinical genetics Counseling note
42349-1
41053-0 - SMN1 gene Mut Anl Bld/T
54449-7
53039-4 - Gene dis anl carrier interp-Imp
8262-8 - Service Cmnt 02-Imp
62385-0 - Recommendation Patient Doc-Imp
55752-0 - Clinical info
8251-1 - Service Cmnt-Imp
49549-9 - Ref lab test method
36908-2 - Gene Mut Tested Bld/T
75608-0 - Citation Ref Lab Test
72486-4 - Lab director name Provider
51969-4 - Gene analysis narr rpt Doc

Result Turnaround Time

8-14 days

Specimen

Whole Blood

Volume

8.5 mL

Minimum Volume

3 mL

Container

Yellow-top (ACD-A) tube or lavender-top (EDTA) tube

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.