On the other hand, Millino et al. found that patients with spinal muscular atrophy type I, a neurodegenerative disorder associated with mutations of the survival MN gene and characterized by muscle weakness and atrophy caused by degeneration of spinal MNs, showed reduced expression of the genes involved in the IGF/PI3K/Akt pathway with an overexpression of the IGF-1R gene.33 Here, IGF1 is linked to spinal muscular atrophy, type 1.