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GTR Home > Tests > Mitochondrial Non Syndromic Hearing Loss and Deafness


Test order codeHelp: 2257

Test name


Mitochondrial Non Syndromic Hearing Loss and Deafness

Purpose of the test


This is a clinical test intended for Help: Diagnosis, Mutation Confirmation



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How to order


Not provided

Specimen source

Peripheral (whole) blood


Molecular Genetics
TTargeted variant analysis
Uni-directional Sanger sequencing

Summary of what is tested

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Clinical utility


Establish or confirm diagnosis


Clinical validity


The Sensorineural hearing loss (SNHL) caused by ototoxicity due to aminoglycosides is mainly due to pathogenic variants in the MT-RNR1 gene of the mtDNA, the A1555G variant is the most frequent. Less frequent variants such as C1494T and A827G in this same gene have also been detected. Although it has been reported that the effect of A827G is controversial, it was detected in a subject with SNHL in our laboratory. On the other hand, in the SNHL of onset in childhood, variants in MT-TS1 gene have been associated (A7443G, A7444G and A7445G) of mtDNA, being changes in 7445 codon the most frequent.

  • 1. Genereviews: NBK1422

Test services

  • Clinical Testing/Confirmation of Mutations Identified Previously

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