SMN1, SMN2 Del/Dup Test
SMA diagnosis & carrier screening test
The faster the diagnosis is, the greater outcome is achievable.
Does it simply mean that the baby is developing a bit slowly?
Some symptoms may represent Spinal Muscular Atrophy.
What is Spinal Muscular Atrophy ?
SMA (Spinal Muscular Atrophy) is a hereditary neuromuscular disorder caused by mutations in the SMN gene, which is responsible for maintaining motor neurons. Due to insufficient production of motor neurons, individuals with SMA experience genetic neuromuscular conditions.
In a healthy person, SMN gene produces a protein—called survival motor neuron protein or SMN protein—that is critical to the function of the nerves that control our muscles. Without it, those nerve cells cannot properly function and eventually die, leading to debilitating and sometimes fatal muscle weakness.
[The function of SMN gene]
SMN1
- Major gene produces SMN protein
- SMA occurs only when there are variants in both copies of the SMN1 gene.
SMN2
- Minor gene produces SMN protein
- Only 10% of produced SMN protein function normally
- All SMA patients have one or more SMN2 genes, and the number of SMN2 genes varies among individuals.
- The more the number of SMN2 genes, the less severe the symptoms tend to appear.
What is SMN1, SMN2 del/dup test ?
Among the SMN1 and SMN2 genes associated with this disease, the SMN1 gene is a major gene related to disease development.
95% of patients are homozygous for the SMN1 gene deletion mutation, and the remaining 5% are heterozygous
for the deletion mutation and point mutation.
This test is a test to confirm deletion and duplication of exon 7 and 8 of SMN1&SMN2 genes using the MLPA
(Multiplex Ligation dependent Probe Amplification) method.
What is the symptoms of Spinal Muscular Atrophy?
4 Types of Spinal Muscular Atrophy
- Spinal Muscular Atrophy (SMA) is classified into several types based on the age of symptom onset, severity, variants and CNV of the SMN1 and SMN2 genes.
- Especially, SMA Type 1, also known as Werdning-Hoffman disease, is the most common type of SMA. It is characterized by significant symptoms and has the shortest life expectancy among the different types of SMA.
How does SMN work?
Discuss testing and collect
your patient’s blood sample and
send it to GC Genome Laboratory.
Receive results within
14 days and discuss
with your patient.
If you need genetic counseling
based on the result,
please contact your account manager.
