AQP4 and proximal spinal muscular atrophy: While neurological disorders such as amyotrophic lateral sclerosis (ALS) show reduced mRNA AQP4 expression, as well as protein levels in the skeletal muscle [110], it would be intriguing to examine these findings in spinal muscular atrophy (SMA), one of the most common genetic neuromuscular disorder affecting infants worldwide [111].