Spinal Muscular Atrophy (SMA) SMN1/SMN2 Deletion Duplication Analysis using MLPA (Multiplex Ligation-dependent Probe Amplification)

• Test Name: Spinal Muscular Atrophy (SMA) SMN1/SMN2 Deletion Duplication Analysis using MLPA (Multiplex Ligation-dependent Probe Amplification).
• Test Type: Genetic test used to detect deletions and duplications in the SMN1 and SMN2 genes.
• Specimen Required: Blood sample.
• Methodology: MLPA technology is used to analyze the presence or absence of copies of the SMN1 and SMN2 genes.
• Purpose: This test identifies deletions or duplications in the SMN1 gene, which is associated with Spinal Muscular Atrophy (SMA), and assesses the copy number of the SMN2 gene

• Diagnosis of SMA: Primarily used to diagnose Spinal Muscular Atrophy by detecting mutations in the SMN1 gene.
• Carrier Testing: Determines whether a person is a carrier of SMA, even if they do not have symptoms.
• Prenatal and Preconception Screening: Offers genetic screening for couples at risk of having a child with SMA.
• Prognosis Estimation: Evaluate the copy number of SMN2, which can influence the severity of the disease.

• SMN1 Gene Deletion Detection: Detects deletions in the SMN1 gene, which are the most common cause of SMA.
• SMN2 Gene Copy Number: Assesses the number of copies of the SMN2 gene, which can modify the severity of the disease.
• Carrier Status: Determines if an individual is a carrier of an SMN1 deletion, which has implications for family planning.

• SMN1 Deletion: A deletion in the SMN1 gene is diagnostic for SMA or carrier status, depending on the number of functional gene copies.
• SMN2 Copy Number: A higher number of SMN2 gene copies is generally associated with a milder form of SMA.
• Carrier Status: Individuals with one copy of SMN1 are considered carriers, while those with two deleted copies typically have SMA.

• Turnaround Time: Results are generally available within 1-2 weeks.
• Report Format: The results are presented with information about SMN1 deletions and the number of SMN2 copies.
• Clinical Follow-Up: Based on the test results, genetic counselling may be recommended to discuss prognosis, carrier status, or family planning options.

Q. What is the purpose of the SMN1/SMN2 Deletion Duplication Analysis?
This test is used to detect mutations in the SMN1 gene, which causes Spinal Muscular Atrophy (SMA), and to assess the SMN2 gene copy number, which influences disease severity
 

Q. Why would someone need an SMN1/SMN2 Deletion Duplication Analysis?
The test is recommended for individuals suspected of having SMA, those with a family history of the disease, or couples seeking carrier screening
 

Q. What does it mean if I test positive for an SMN1 deletion?
A positive result indicates either a diagnosis of SMA or carrier status, depending on whether both copies of SMN1 are deleted
 

Q. Can the test predict the severity of Spinal Muscular Atrophy?
Yes, the number of SMN2 gene copies can give an indication of how severe the symptoms of SMA might be, with more copies typically linked to milder forms of the disease
 

Q. What is the difference between SMN1 and SMN2 genes?
SMN1 is the primary gene responsible for producing functional survival motor neuron protein, while SMN2 produces a smaller amount of functional protein and modulates the severity of SMA
 

Q. Who should consider carrier testing for SMA?
Carrier testing is recommended for individuals with a family history of SMA, partners of known carriers, or couples planning a pregnancy
 

Q. How long does it take to get the test results?
Test results are typically available within 1-2 weeks and should be discussed with a genetic counsellor or physician