MitochondrialtRNAmutationsareoneoftheimportantcausesofbothsyndromicandnon-syndromicdeafness.Ofthose,syndromicdeafness-associatedtRNAmutationssuchastRNALeu(UUR)3243A>Gareoftenpresentinheteroplasmy,whilenon-syndromicdeafness-associatedtRNAmutationsincludingtRNASer(UCN)7445A>Gareofteninhomplasmyorinhighlevelsofheteroplasmy.ThesetRNAmutationsaretheprimarymutationsleadingtohearingloss.However,othertRNAmutationssuchastRNAThr15927G>AandtRNASer(UCN)7444G>AmayactinsynergywiththeprimarymitochondrialDNAmutations,modulatingthephenotypicmanifestationoftheprimarymitochondrialDNAmutations.ThesestRNAmutationscausestructuralandfunctionalalteration.AfailureintRNAmetabolismcausedbythesetRNAmutationsimpairedmitochondrialtranslationandrespiration,therebycausingmitochondrialdysfunctionsresponsiblefordeafness.Thesedataoffervaluableinformationfortheearlydiagnosis,managementandtreatmentofmaternallyinheriteddeafness.
