The non-sense mutations in the OTOF gene producing truncated versions of protein causing DFNB9 deafness has been well-established by the researchers using in vitro and in vivo models in their experiments (Pangršič et al., 2012; Chatterjee et al., 2015; Hams et al., 2017). This evidence concerns the gene OTOF and autosomal recessive nonsyndromic hearing loss 9.