Name of the Procedure:

SMN1 (Survival of Motor Neuron 1, Telomeric) Gene Analysis; Dosage/Deletion Analysis (e.g., Carrier Testing), includes SMN2 (Survival of Motor Neuron 2, Centromeric) Analysis, if performed

Summary

This genetic test analyzes the SMN1 and SMN2 genes to detect deletions or alterations in the gene dosage. It helps determine if an individual is a carrier of spinal muscular atrophy (SMA), a genetic condition that affects motor neurons and muscle movement.

Purpose

The procedure aims to identify carriers of spinal muscular atrophy (SMA) and assess the risk of passing the condition to offspring. It also helps diagnose individuals suspected of having SMA.

Indications

• Family history of spinal muscular atrophy.
• Couples planning to conceive, especially if one partner has a family history of SMA.
• Individuals showing symptoms of SMA, such as muscle weakness and atrophy.
• Prenatal testing if there is a known family history of SMA.

Preparation

• No special preparation required.
• Inform the healthcare provider of any medications being taken.
• A family history may be reviewed and genetic counseling offered.

Procedure Description

1. A blood sample is collected, typically from a vein in the arm.
2. The sample is sent to a laboratory where DNA is extracted.
3. The SMN1 and SMN2 genes are analyzed using molecular genetic techniques.
4. Dosage analysis is performed to detect deletions or duplications in the SMN1 gene.
5. If applicable, SMN2 gene analysis is conducted to provide additional information on disease severity and carrier status.

Duration

• Blood sample collection: Approximately 10-15 minutes.
• Laboratory analysis: Several days to weeks, depending on the laboratory's processing time.

Setting

• Blood sample collection: Outpatient clinic, hospital, or specialized laboratory setting.
• Laboratory analysis: Genetics laboratory.

Personnel

• Phlebotomist or nurse for blood sample collection.
• Laboratory technicians or geneticists for genetic analysis.

Risks and Complications

• Minimal risks associated with blood sample collection (e.g., bruising, slight discomfort).
• No significant complications related to the genetic analysis itself.

Benefits

• Identification of carrier status for spinal muscular atrophy.
• Informed decision-making for family planning.
• Early diagnosis and potential management options for affected individuals.

Recovery

• No recovery time is needed for the blood draw.
• Follow-up genetic counseling sessions may be recommended to discuss results and implications.

Alternatives

• Other genetic tests targeting specific mutations associated with SMA.
• Prenatal genetic diagnosis through amniocentesis or chorionic villus sampling (CVS).
• Pre-implantation genetic diagnosis (PGD) for those undergoing in vitro fertilization (IVF).

Patient Experience

• Little to no pain from the blood draw, similar to a routine blood test.
• Anxiety or emotional distress related to genetic testing and its potential implications can be managed through genetic counseling and support.