SMN1 (survival of motor neuron 1, telomeric) (eg, spinal muscular atrophy) gene analysis; full gene sequence
CPT4 code
Name of the Procedure:
Full Gene Sequence Analysis of SMN1 (Survival of Motor Neuron 1, Telomeric) for Spinal Muscular Atrophy
Summary
This procedure involves sequencing the entire SMN1 gene to detect mutations that may cause spinal muscular atrophy (SMA), a genetic disorder affecting the motor neurons in the spinal cord, leading to muscle weakness and atrophy.
Purpose
The main aim is to diagnose SMA by identifying mutations in the SMN1 gene. By confirming the genetic basis of the disease, healthcare providers can plan appropriate interventions and management strategies to improve patient outcomes.
Indications
- Symptoms of muscle weakness and atrophy, particularly in infants and young children.
- Family history of SMA or known carriers of SMN1 mutations.
- Prenatal testing if there is a known risk of SMA.
Preparation
- No specific preparation such as fasting is generally required.
- Collection of a blood sample or buccal swab for DNA extraction.
- Physicians may review the patient's medical history and any prior genetic testing results.
Procedure Description
- A sample of the patient’s DNA is collected, usually from blood or a buccal swab.
- The DNA is then subjected to sequencing to analyze the full sequence of the SMN1 gene.
- Advanced laboratory techniques and sequencing machines are used to detect mutations.
- No anesthesia or sedation is needed as it is a non-invasive procedure.
Duration
The actual sample collection only takes several minutes. The full sequencing and analysis can take several weeks to return results.
Setting
The sample collection can be performed in a variety of settings, such as a doctor's office, clinic, or hospital. Sequencing is performed in a specialized genetic laboratory.
Personnel
- Sample collection may be done by a nurse or phlebotomist.
- Genetic analysis is conducted by medical laboratory technologists and geneticists.
- A genetic counselor and physician may interpret the results.
Risks and Complications
- Minimal risk associated with sample collection (e.g., slight pain, bruising from a blood draw).
- Rare risk of inconclusive results which may require repeat testing.
Benefits
- Accurate diagnosis of SMA, allowing for early intervention and management.
- Genetic counseling for families to understand the inheritance patterns and risks for future pregnancies.
- Possibility of participating in clinical trials for new treatments.
Recovery
- No recovery time required from the sample collection process.
- Patients can return to their normal activities immediately after.
Alternatives
- Multiplex ligation-dependent probe amplification (MLPA), a less comprehensive test for specific deletion analysis.
- Carrier testing in family planning rather than full gene sequencing.
Patient Experience
- The sample collection (blood draw or buccal swab) is generally quick and involves minimal discomfort.
- Waiting for results can cause anxiety; genetic counseling is recommended for support.
- No pain associated with the sequencing and analysis process.