GRHL2 and hearing loss disorder: Subsequent studies have reported that mutations and/or gene polymorphisms in GRHL2 are implicated in hereditary and acquired hearing loss such as age-related hearing impairment, non-syndromic hearing loss, sudden sensorineural hearing loss and noise-induced hearing loss in Chinese, Korean, Roma and Hungarian populations (Kim et al., 2015; Zhang et al., 2015; Lin et al., 2016; Xu et al., 2016; Li X. et al., 2019; Matyas et al., 2019; Wu et al., 2020).