SMN2 and proximal spinal muscular atrophy: Risdiplam (Evrysdi®) is another SMN2 mRNA splicing modifier approved for the treatment of SMA in patients 2 months of age and older (in the EU) or without age limits (in the USA), with a clinical diagnosis of type 1, type 2, and type 3 SMA or with one to four SMN2 copies (13, 14).