[Prevalence of the A1555G mutation in the mitochondrial DNA in patients with cochlear or vestibular damage due to aminoglycoside-induced ototoxicity].
OBJECTIVE
To determine the frequency of the A1555G mutation in the mitochondrial genome among Spanish patients with aminoglycoside-induced ototoxicity.


METHODS
We screened 25 unrelated cases, totalling 39 individuals with cochlear or vestibular damage due to aminoglycoside-induced ototoxicity. This group was made up of 18 subjects from 4 unrelated families with a history of aminoglycoside ototoxicity in more than one relative, 8 subjects from 8 families that also had other relatives with hearing loss in absence of aminoglycoside exposure, and 13 sporadic cases. Among the 13 sporadic cases, there were 3 patients with vestibular involvement. Detection of the A1555G mutation was seen by mean of techniques for molecular diagnosis.


RESULTS
The A1555G mutation was identified in all of the individuals from 4 families with aminoglycoside-induced cochlear damage and in 6 of 8 individuals with familial hearing loss. None of the sporadic cases carried the mutation.


CONCLUSIONS
A high proportion of patients with cochlear damage due to aminoglycoside ototoxicity and having a familial history of hearing loss, related or not to aminoglycoside exposure, harbor the A1555G mutation.
Servicio de ORL, Hospital Universitario Marqués de Valdecilla, Santander.
J
J
Gallo-Terán
B
B
Arellano
C
C
Morales-Angulo
S
S
Modamio-Høybjør
M A
MA
Moreno-Pelayo
R
R
Ramírez-Camacho
I
I
del Castillo
F
F
Moreno
D000293:Adolescent; D000328:Adult; D000368:Aged; D000617:Aminoglycosides / Q000009:adverse effects*; D004272:DNA, Mitochondrial / Q000235:genetics*; D005260:Female; D034381:Hearing Loss / Q000139:chemically induced* / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D013030:Spain
D000617:Aminoglycosides; D004272:DNA, Mitochondrial