The antiapoptotic role of SMN (Anderton et al., 2013) and the activation of apoptotic processes through the PI3K-Akt neuronal survival pathway has been stablished in SMA (Sansa et al., 2021a) and has been associated with CAPN1 loss of function in cerebellar ataxia (Wang et al., 2016). This evidence concerns the gene CAPN1 and proximal spinal muscular atrophy.