USH1C and Usher syndrome: Almost all the genes studied are expressed in the hair cells, and they include the genes defective in Usher syndrome, such as the harmonin (USH1C) (Pan et al., 2017), sans (USH1G) (Emptoz et al., 2017), clarin-1 (USH3A) (Geng et al., 2017; Dulon et al., 2018; György et al., 2019a), whirlin (USH2D) (Isgrig et al., 2017) genes, and the genes encoding SYNE4 (Taiber et al., 2021), the mechano-electrical transduction channel proteins TMC1/2 (Wu et al., 2021; Nist-Lund et al., 2019), and the synaptic proteins VGLUT3 (Akil et al., 2012) and otoferlin (Akil et al., 2019; Al-Moyed et al., 2019).