Diagnostics Service of
the Molecular Otolaryngology & Renal Research Laboratories is a Joint
Commission-approved CLIA-accredited diagnostic laboratory that
offers mutation screening of several genes.
MTRNR1 (OMIM# 561000)
Hearing loss as a result of aminoglycoside exposure (OMIM# 580000)
has been reported to involve at least 2 mitochondrial mutations,
C1494T and A1555G of the 12S rRNA gene. Damage to the inner ear
is caused by reactive oxygen species, which provide a common
pathway not only for aminoglycoside toxicity, but also for
cisplatin toxicity and noise-induced hearing loss. MORL offers
screening for both of these mutations.
MORL screening methodology
Samples are amplified with an oligonucleotide
primer pair that flanks the A1555G and C1494T mutations within
the MTRNR1 gene,
followed by sequencing.
Sensitivity is greater than 99%.
Turn around time is approximately 3 months
(Average TAT - 26 days).
Indications for screening
This test is appropriate if aminoglycoside-induced
ototoxcicity is suspected.
GeneTests GeneReviews – Nonsyndromic
Hearing Loss, Mitochondrial
Casano, R. A. et al.: Hearing
loss due to the mitochondrial A1555G mutation in Italian
J Med Genet. 79(5):388-91, 1998.
PubMed ID: 9779807
Zhao, H. et al: Maternally
inherited aminoglycoside-induced and nonsyndromic deafness is
associated with the novel C1494T mutation in the mitochondrial
12S rRNA gene in a large Chinese family. Am.
J. Hum. Genet. 74: 139-152, 2004.
PubMed ID: 14681830