2025 CPT code 81336
Effective Date: N/A Pathology and Laboratory Procedures - Molecular Pathology Procedures Feed
SMN1 (survival of motor neuron 1, telomeric) (e.g., spinal muscular atrophy) gene analysis; full gene sequence
Modifier 26 can be used if a physician performs only the professional component (interpretation and report).
Medical necessity is established by the presence of signs, symptoms, or family history suggestive of SMA, or for carrier screening in individuals with a family history of SMA.
The laboratory analyst performs all technical aspects of this test, from extracting the DNA to analyzing the SMN1 gene sequence.
In simple words: This test analyzes the complete genetic code of the SMN1 gene, which is important for muscle function. It's commonly used to diagnose a disease called spinal muscular atrophy (SMA), a condition that causes muscle weakness and wasting.
This code represents the analysis of the entire SMN1 gene sequence. It is often used to diagnose spinal muscular atrophy (SMA), but can be used for other purposes.
Example 1: A newborn exhibits symptoms of muscle weakness and a pediatrician orders this test to confirm or rule out spinal muscular atrophy (SMA)., An adult with unexplained muscle weakness and atrophy undergoes genetic testing, including SMN1 full gene sequencing, to determine a possible genetic cause., A couple planning to have children undergoes carrier screening for SMA, which includes this test to identify potential deletions or mutations in the SMN1 gene.
Proper documentation should include the reason for testing (e.g., suspected SMA, carrier screening), relevant clinical findings, and family history.
- Specialties:Genetics, Neurology, Pediatrics
- Place of Service:Independent Laboratory, Hospital Laboratory