The importance of an early SMA diagnosis and trial enrollment has received increased attention recently following the preliminary reports from a phase 2, open‐label, dose‐escalation study of Nusinersen (an antisense oligonucleotide that modifies SMN2 RNA splicing) (Chiriboga et al., 2016; Finkel et al., 2016; Hache et al., 2016). This evidence concerns the gene SMN2 and proximal spinal muscular atrophy.