SMN1 and proximal spinal muscular atrophy: Two methods for SMA NBS use dried blood spot (DBS) samples in a Real-Time PCR (RT-PCR) or digital droplet PCR (ddPCR) assay to detect a homozygous SMN1 exon 7 deletion which is responsible for >95% of SMA cases (Taylor et al., 2015; Vidal-Folch et al., 2018; Jiang et al., 2020; Romanelli Tavares et al., 2021).