SMA is a childhood neuromuscular disorder that is characterized by degeneration of anterior horn cells of the spinal cord. This disease is inherited and transmitted in an autosomal recessive pattern.
WHAT IS THE PURPOSE OF THIS TEST?
The test is conducted to detect the deletion of exons 7 & 8 of the Survival Motor Neuron 1 (SMN 1) gene that is the responsible gene for this disease. Normal healthy individuals have both SMN1 and SMN2 but 90% of SMA patients have no SMN1 gene. This test detects over 90% of the SMA patients while the other 10% of patients will have other types of mutations.
WHAT IS REQUIRED TO PERFORM THIS TEST?
You will be asked to collect 2.5 - 3 ml of blood in EDTA container. DNA will be extracted from this blood sample using a commercial kit. The genomic DNA of the sample will be amplified for exons 7 and 8 using a thermocycler. The PCR product will be digested using a restriction enzyme to discriminate between SMN1 and SMN2 genes for the deletion analysis.