SRRM2 and proximal spinal muscular atrophy: Defects in protein homeostasis, aggregation, RNA binding proteins and RNA processing lead to pathologic physiological changes in PD, as is the case for other neurodegenerative diseases, like amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA) (Brinegar and Cooper, 2016, Conlon and Manley, 2017, Mann and Donnelly, 2021).