SMN1 and proximal spinal muscular atrophy: This drug has been approved for two groups of patients (1, patients with 5q SMA with a bi-allelic mutation in the SMN1 gene and a clinical diagnosis of SMA1; 2, patients with 5q SMA with a bi-allelic mutation in the SMN1 gene and up to 3 copies of the SMN2 gene), but there are no data on age or weight limits.