Moreover, SMA, along with general weakness and atrophy of spinal cord motor neurons and skeletal muscles, is also a severe autosomal recessive disease caused mainly by nucleotide mutations of the survival motor neuron 1 (SMN1) gene (Bergin et al. 1997; Schrank et al. 1997; Hamilton and Gillingwater 2013). The gene discussed is SMN1; the disease is proximal spinal muscular atrophy.