MT-RNR1 663A>G is assigned an uncertain risk of aminoglycoside-induced hearing loss based on inadequate evidence. This variant has been identified in individuals with aminoglycoside-induced hearing loss but also in controls after aminoglycoside exposure (8414970, 7689389, 7550368). Therefore, consensus among experts is that there is uncertain risk of aminoglycoside-induced hearing loss associated with this variant.