ACTB and proximal spinal muscular atrophy: The latter study involved 27 patients selected out of 51 with spinal muscular atrophy 1 (SMA1) disorder to receive an injection of AAV9-based vector (6 × 1013, 1.2 × 1014 and 2.4 × 1014 vp per patient) designed to express the SMN protein under the control of hybrid CMV/β-actin promoter (ZOLGENSMA).