Chinese researchers tested five different laboratory techniques designed to determine the status of the SMN1 and SMN2 genes in 516 reference samples.
- These techniques included: MLPA, quantitative PCR (qPCR), digital microdroplet PCR (ddPCR), high-resolution analysis (HRM) and capillary electrophoresis PCR (CE PCR);
- MLPA remains the reference method, but requires considerable laboratory time and resources,
- the other four techniques have sensitivities and specificities very close to MLPA,
- They can, however, determine the presence of a SMN1 gene deletion, usually at a lower cost, and provide a great deal of information on the SMN2 gene copy number.
However, these techniques have their limitations, as they do not detect subjects with a 2-0 SMN1 genotype. This comparison will be very useful for decision-makers in the context of neonatal screening and/or screening for SMA heterozygotes in the general population.