SMN1 and proximal spinal muscular atrophy: Current molecular methodologies for the detection and diagnosis of SMA by revealing SMN1 deletion and by SMN1 and SMN2 gene quantitation, respectively, include single-strand conformation polymorphism, restriction fragment length polymorphism, real-time polymerase chain reaction (RT-PCR), denaturing high-performance liquid chromatography, multiplex ligation probe amplification (MLPA), quantitative PCR (qPCR) and competitive PCR, high-resolution melting analysis, and liquid microbead assay [8].