SMN2 and proximal spinal muscular atrophy: FDA: SMA patients less than 2 years of age with bi-allelic mutations in the SMN1 gene. EMA: patients with 5q SMA with a bi-allelic mutation in the SMN1 gene and a clinical diagnosis of SMA type 1, or patients with 5q SMA with a bi-allelic mutation in the SMN1 gene and up to 3 copies of the SMN2 gene