CDC42 and sensorineural hearing loss disorder: As proposed by Hamada et al. (2020), the p.Tyr64Cys mutation affects Cdc42-dependent cell polarity organization, and it is critical for axon elongation, dendritic arbor formation and migration during the corticogenesis; these processes could underlie the pathophysiology of ID [16,17,21] and, eventually, sensorineural hearing loss.