SMN1 and proximal spinal muscular atrophy: The FDA has approved the gene therapy products based on two viral vectors, which are both AAV vectors: LUXTURNA (Spark Therapeutics, Inc.)for the treatment of patients with confirmed biallelic RPE65 mutation-associated retinal dystrophy and ZOLGENSMA for the treatment of pediatric patients below two years of age having spinal muscular atrophy (SMA) with bi-allelic mutations in the survival motor neuron 1 (SMN1) gene.