For example, mutations of several genes involved in oestrogen signalling lead to hearing impairment, such as Esr2, Esrrb and Esrrg in mice and ESRRB in human deafness type DFNB35, and hearing impairment is a feature of oestrogen deficiency in Turner syndrome in humans (Chen & Nathans, 2007; Collin et al, 2008; Meltser et al, 2008; Hederstierna et al, 2009; Simonoska et al, 2009; Nolan et al, 2013). This evidence concerns the gene ESR2 and hearing loss disorder.