Spinal Muscular Atrophy With Respiratory Distress (SMARD)

Also known as: distal spinal muscular atrophy (DSMA1), distal hereditary motor neuronopathy type VI (dHMN6 or HMN6)


Protein: immunoglobulin mu-binding protein 2

Clinical Characteristics

  • Sudden onset of respiratory symptoms:
    • Stridor/weak cry
    • Diaphragmatic paralysis within first year of life
  • Muscle weakness:
    • Initially distal, progressing to generalized
  • Intrauterine growth retardation
  • Premature birth
  • Foot deformities
  • Autonomic nervous system dysfunction
  • Seizures
  • Phenotypic variability between and within families

Inheritance pattern: Autosomal recessive

What Can Be Learned From This Test

Testing is performed by sequencing all exons and partial intronic regions of IGHMBP2. This will detect point mutations, small deletions and small insertions. It will not detect a partial or whole gene deletion or duplication.

Sample Requirements

Draw 2ml–4ml of blood in EDTA/purple-top tube (minimum of 1ml–2ml for infants).

Turnaround time: 10-14 business days

CPT Codes and Cost

Full Gene Sequencing

  • Code: 81479
  • Cost: $1,500

Known Variant Testing

  • Code: 81479
  • Cost: $225

Additional Information

OMIM entries