Spinal Muscle Atrophy (SMA)


  • Evidence of degeneration and loss of anterior horn cells (i.e. lower motor neurons) in the spinal cord and brainstem
  • A history of motor difficulties
  • Evidence of motor unit disease on physical examination
  • Diagnostic changes in the SMN1 gene
  • Routine carrier screening of the general population
  • SMA Carrier Risk in People with No Family History of SMA:
  • Caucasian – 1 in 35
  • Ashkenazi Jewish – 1 in 41
  • Asian – 1 in 53
  • African American – 1 in 66
  • Hispanic – 1 in 117

The symptoms of Spinal muscular atrophy Types I, II, and III include: weakness and wasting of voluntary muscles in the arms and legs of infants and children.

Collection Procedure

Lavender top tube (EDTA).  Label tube with patient’s name and date of birth. A completed test requisition form must be included with every sample.  A transport kit is available upon request.

Specimen Requirements

10cc whole blood

Specimen Container

Lavender top tube (EDTA)

Transport Temperature

Room temperature (DO NOT refrigerate, freeze or centrifuge)


Laboratory Testing for Spinal Muscle Atrophy is performed Polymerase Chain Reaction (PCR), Quantitative Dose Analysis

Causes for Rejection

Frozen specimen, clotted or hemolysed, inappropriate collection tube 

Turnaround Time

14 days