Distortion-product otoacoustic emissions at ultra-high frequencies in parents of individuals with autosomal recessive hearing loss.
OBJECTIVE
To evaluate the cochlear function of parents of individuals with autosomal recessive gene Gap Junction Protein Beta-2 hearing loss by ultra-high frequencies distortion-product otoacoustic emissions (DPOAEs), compared with responses of a control group matched for age and gender.


METHODS
We studied 56 subjects aged from 20 to 58 years, divided into two groups. The study group comprised 28 parents of hearing-impaired patients due to autosomal recessive inheritance, 14 females aged 20.0-55.0 years (mean 32.8 years) and 14 males aged 20.0-58.0 years (mean 35.2 years). Control group was composed of normal hearing individuals, 14 males and 14 females age-matched to the study group. The subjects underwent tests for audiometry, tympanometry, and DPOAE in the frequency range of 9.000-16.000 Hz.


RESULTS
We found 64.3% of normal results of DPOAE in the study group compared to 91.1% in the control. There were significant differences between groups in the ears and DPOAE responses, and the mean level of response was in 10 dBNPS in study group and 14 dBNPS in the control. The Pearson's correlation between age and DPOAE in ultra-high frequencies showed no statistical significance.


CONCLUSIONS
DPOAE at ultra-high frequencies were able to identify individuals from both groups, suggesting that heterozygous individuals for the Gap Junction Protein Beta-2 gene mutation may have damage to the cochlear function before clinical manifestation in audiometry.
Faculdade Ingá, Maringá, PR, Brazil.
Jaqueline Medeiros de
JM
Mello
Universidade Estadual de Maringá, Maringá, PR, Brazil.
Valter Augusto
VA
Della-Rosa
Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil.
Renata Mota Mamede
RM
Carvallo
D000328:Adult; D001309:Auditory Threshold; D016022:Case-Control Studies; D005260:Female; D005808:Genes, Recessive; D006316:Hearing Loss, High-Frequency / Q000175:diagnosis / Q000235:genetics*; D006579:Heterozygote; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics; D017084:Otoacoustic Emissions, Spontaneous / Q000235:genetics* / Q000502:physiology; D010290:Parents; D055815:Young Adult