Results of cochlear implantation in two children with mutations in the OTOF gene (original) (raw)
Related papers
Abnormal Cochlear Potentials from Deaf Patients with Mutations in the Otoferlin Gene
Journal of the Association for Research in Otolaryngology, 2009
Otoferlin is involved in neurotransmitter release at the synapse between inner hair cells (IHCs) and auditory nerve fibres, and mutations in the OTOF gene result in severe to profound hearing loss. Abnormal soundevoked cochlear potentials were recorded with transtympanic electrocochleography from four children with otoferlin (OTOF) mutations to evaluate physiological effects in humans of abnormal neurotransmitter release from IHCs. The subjects were profoundly deaf with absent auditory brainstem responses and preserved otoacoustic emissions consistent with auditory neuropathy. Two children were compound heterozygotes for mutations c.2732_2735dupAGCT and p.Ala964Glu; one subject was homozygous for mutation p.Phe1795Cys, and one was compound heterozygote for two novel mutations c.1609delG in exon 16 and c.1966delC in exon 18. Cochlear potentials evoked by clicks from 60 to 120 dB peak equivalent sound pressure level were compared to recordings obtained from 16 normally hearing children. Cochlear microphonic (CM) was recorded with normal amplitudes from all but one ear. After cancelling CM, cochlear potentials were of negative polarity with reduced amplitude and prolonged duration compared to controls. These cochlear potentials were recorded as low as 50-90 dB below behavioural thresholds in contrast to the close correlation in controls between cochlear potentials and behavioural threshold. Summating potential was identified in five out of eight ears with normal latency whilst auditory nerve compound action potentials were either absent or of low amplitude. Stimulation at high rates reduced amplitude and duration of the prolonged potentials, consistent with neural generation. This study suggests that mechano-electrical transduction and cochlear amplification are normal in patients with OTOF mutations. The low-amplitude prolonged negative potentials are consistent with decreased neurotransmitter release resulting in abnormal dendritic activation and impairment of auditory nerve firing.
Cochlear implantation in common forms of genetic deafness
International Journal of Pediatric Otorhinolaryngology, 2010
Genetic factors are among the main etiologies of severe to profound hearing loss and may play an important role in cochlear implantation (CI) outcomes. While genes for common forms of deafness have been cloned, efforts to correlate the functional outcome of CIs with a genetic form of deafness carried by the patient have been largely anecdotal to date. It has been suggested that the differences in auditory performance may be explained by differences in the number of surviving spiral ganglion cells, etiology of hearing loss, and other factors. Knowledge of the specific loci and mutations involved in patients who receive cochlear implants may elucidate other factors related to CI performance. In this review article, current knowledge of cochlear implants for hereditary hearing loss will be discussed with an emphasis on relevant clinical genotype-phenotype correlations.
Clinical genetics, 2016
Auditory neuropathy spectrum disorder is one of the most common diseases leading to hearing and speech communication barriers in infants and young children. The OTOF gene is the first gene identified for autosomal recessive non-syndromic ANSD and patients with OTOF mutations have shown marked improvement of auditory functions from the cochlear implantation, but the true involvement of OTOF mutations in Chinese ANSD patients are still unknown which precludes the effective management of this disease. Here, we investigated the contribution of OTOF mutations to congenital ANSD patients in China. In all, 37 infants and young Children with ANSD were screened for all the exons of OTOF gene,of them 34 patients had no neonatal risk factors who were considered as congenital ANSD. The clinical manifestation and audiometric features were also investigated and compared in patients with and without OTOF mutations. In all, 14 of these subjects were shown to carry two or three mutant alleles of OTO...
OPA1-related auditory neuropathy: site of lesion and outcome of cochlear implantation
Brain, 2015
Hearing impairment is the second most prevalent clinical feature after optic atrophy in dominant optic atrophy associated with mutations in the OPA1 gene. In this study we characterized the hearing dysfunction in OPA1-linked disorders and provided effective rehabilitative options to improve speech perception. We studied two groups of OPA1 subjects, one comprising 11 patients (seven males; age range 13-79 years) carrying OPA1 mutations inducing haploinsufficiency, the other, 10 subjects (three males; age range 5-58 years) carrying OPA1 missense mutations. Both groups underwent audiometric assessment with pure tone and speech perception evaluation, and otoacoustic emissions and auditory brainstem response recording. Cochlear potentials were recorded through transtympanic electrocochleography from the group of patients harbouring OPA1 missense mutations and were compared to recordings obtained from 20 control subjects with normal hearing and from 19 subjects with cochlear hearing loss. Eight patients carrying OPA1 missense mutations underwent cochlear implantation. Speech perception measures and electrically-evoked auditory nerve and brainstem responses were obtained after 1 year of cochlear implant use. Nine of 11 patients carrying OPA1 mutations inducing haploinsufficiency had normal hearing function. In contrast, all but one subject harbouring OPA1 missense mutations displayed impaired speech perception, abnormal brainstem responses and presence of otoacoustic emissions consistent with auditory neuropathy. In electrocochleography recordings, cochlear microphonic had enhanced amplitudes while summating potential showed normal latency and peak amplitude consistent with preservation of both outer and inner hair cell activities. After cancelling the cochlear microphonic, the synchronized neural response seen in both normally-hearing controls and subjects with cochlear hearing loss was replaced by a prolonged, low-amplitude negative potential that decreased in both amplitude and duration during rapid stimulation consistent with neural generation. The use of cochlear implant improved speech perception in all but one patient. Brainstem potentials were recorded in response to electrical stimulation in five of six subjects, whereas no compound action potential was evoked from the auditory nerve through the cochlear implant. These findings indicate that underlying the hearing impairment in patients carrying OPA1 missense mutations is a disordered synchrony in auditory nerve fibre activity resulting from neural degeneration affecting the terminal dendrites. Cochlear implantation improves speech perception and synchronous activation of auditory pathways by bypassing the site of lesion.
Novel OTOF mutations in Brazilian patients with auditory neuropathy
Journal of Human Genetics, 2009
The OTOF gene encoding otoferlin is associated with auditory neuropathy (AN), a type of non-syndromic deafness. We investigated the contribution of OTOF mutations to AN and to non-syndromic recessive deafness in Brazil. A test for the Q829X mutation was carried out on a sample of 342 unrelated individuals with non-syndromic hearing loss, but none presented this mutation. We selected 48 cases suggestive of autosomal recessive inheritance, plus four familial and seven isolated cases of AN, for genotyping of five microsatellite markers linked to the OTOF gene. The haplotype analysis showed compatibility with linkage in 11 families (including the four families with AN). Samples of the 11 probands from these families and from seven isolated cases of AN were selected for an exon-by-exon screening for mutations in the OTOF gene. Ten different pathogenic variants were detected, among which six are novel. Among the 52 pedigrees with autosomal recessive inheritance (including four familial cases of AN), mutations were identified in 4 (7.7%). Among the 11 probands with AN, seven had at least one pathogenic mutation in the OTOF gene. Mutations in the OTOF gene are frequent causes of AN in Brazil and our results confirm that they are spread worldwide.
Kiss-JG-et al Cochlear implantation for treatment-induced ototoxic deafness Eur Arch Otorhinol 2005
A case is presented where the authors carried out a cochlear implantation on a girl whose deafness was induced by cytostatic agents. The normally hearing child was diagnosed with Langerhans cell histiocytosis at the age of 3 years and received polychemotherapy for almost 2 years. By her 5th year, she started to develop a bilateral, progressive sensorineural hearing loss, necessitating a hearing aid in both ears. While her histiocytosis was cured, her hearing ultimately deteriorated to total deafness on the right and profound hearing loss on the left ear. After 3 years, her hearing aids no longer provided adequate hearing for the postlingually deafened girl. At the age of 14, a cochlear implantation was performed on her right ear with excellent results.
Audiological Medicine, 2011
Objective: Our objective was to compare acoustically-and electrically-evoked potentials of the auditory nerve in patients with postsynaptic or presynaptic auditory neuropathy with underlying mutations in the OPA1 or OTOF gene. Study design: Transtympanic electrocochleography (ECochG) was recorded from two adult patients carrying the R445H OPA1 mutation, and from fi ve children with mutations in the OTOF gene. Cochlear potentials to clicks or tone-bursts were compared to recordings obtained from 16 normally hearing subjects. Electrically-evoked neural responses recorded through the cochlear implant were also obtained. Results: The cochlear microphonic (CM) was recorded from all subjects, with normal amplitudes. After cancelling the CM, cochlear potentials were of negative polarity with reduced amplitude and prolonged duration compared to controls in both groups of patients. Prolonged negative responses were recorded as low as 50-90dB below behavioural threshold in subjects with OTOF mutations whereas in the OPA1 disorder the prolonged potentials were correlated with hearing threshold. A compound action potential (CAP) was superimposed on the prolonged activity at high stimulation intensity in two children with mutations in the OTOF gene while CAPs were absent in the OPA1 disorder. Electrically-evoked compound action potentials (e-CAPs) were only recorded from subjects with OTOF mutations following cochlear implantation. Conclusions: The fi ndings are consistent with abnormal function of distal portions of auditory nerve fi bres in patients carrying the OPA1 mutation whereas the low-threshold prolonged potentials recorded from children with mutations in the OTOF gene are consistent with abnormal neurotransmitter release resulting in reduced dendritic activation and impairment of spike initiation.
The natural history of OTOF-related auditory neuropathy spectrum disorders: a multicenter study
Human Genetics, 2021
OBJECTIVE:To refine the natural history and genotype-phenotype correlations of OTOF-related auditory neuropathy spectrum disorders (ANSD) through the analysis of audiograms and distortion product otoacoustic emissions (DPOAEs) in a diverse cohort of individuals with hearing loss.METHODS:Audiograms and DPOAEs were collected from individuals diagnosed with OTOF-related ANSD by comprehensive genetic testing and from the published literature. Comparative analysis was undertaken to determine genotype-phenotype relationships using a Monte Carlo algorithm.RESULTS:67 audiograms and 25 DPOAEs from 49 unique individuals positive for OTOF-related ANSD were collected. 51 unique OTOF pathogenic variants were identified of which 21 were missense and 30 were loss of function (LoF; nonsense, splice-site, copy number variants, and indels). There was a statistically significant difference in low, middle, and high frequency pure tone average hearing loss thresholds with missense/missense and LoF/missense genotypes (average: 70.9, 76.0, and 73.4 dB hearing loss) compared with LoF/LoF genotypes (average: 88.5, 95.6, and 94.7 dB hearing loss) via Tukey’s test with age as a co-variate (P = 0.0180, 0.0327, and 0.0347 respectively). Hearing declined during adolescence with missense/missense and LoF/missense genotypes with an annual mid-frequency threshold deterioration of 0.87 dB/year and 1.87 dB/year, respectively. 8.5% of measured frequencies via DPOAE were lost per year in individuals with serial tests.CONCLUSIONS:Audioprofiling of OTOF-related ANSD suggests significantly worse hearing with LoF/LoF genotypes. OTOF-related ANSD causes a unique pattern of variably progressive autosomal recessive auditory neuropathy that may be amenable to gene therapy in selected clinical scenarios.