Frequency and specific characteristics of the incomplete partition type III anomaly in children.

OBJECTIVES/HYPOTHESIS: To determine the frequency of the incomplete partition type III anomaly and the genetic and clinical features associated with POU3F4 mutations in children with hearing loss. STUDY DESIGN: Retrospective case series from 2000 to 2014 at the National Hospital Organization Tokyo Medical Center and collaborating hospitals. METHODS: A total of 1,004 patients (from 938 families) who had hearing loss by 10 years of age and had undergone computed tomography scanning of their temporal bones were enrolled in this genetic, clinical, and radiological study. RESULTS: The incomplete partition type III anomaly was identified in six patients (0.6%), each of whom had an enlargement of the vestibular aqueduct at the end close to the vestibule. The six patients also had POU3F4 variants, and a genetic analysis revealed frameshift deletions in three patients, a missense variant in two patients of the same family, and a large deletion in one patient. Three of the six patients with POU3F4 variants were sporadic cases, and in one patient the genetic mutation occurred de novo. CONCLUSIONS: It was indicated that POU3F4 mutations can be predicted by incomplete partition type III anomaly by radiological examination of the inner ear. All six of the patients showed mixed hearing loss, but none showed fluctuations in hearing, which may be related to the lack of vestibular aqueduct enlargement at the operculum. LEVEL OF EVIDENCE: 4 Laryngoscope, 127:1663-1669, 2017.

International Pediatric Otolaryngology Group (IPOG) consensus recommendations: Hearing loss in the pediatric patient.

OBJECTIVE: To provide recommendations for the workup of hearing loss in the pediatric patient. METHODS: Expert opinion by the members of the International Pediatric Otolaryngology Group. RESULTS: Consensus recommendations include initial screening and diagnosis as well as the workup of sensorineural, conductive and mixed hearing loss in children. The consensus statement discusses the role of genetic testing and imaging and provides algorithms to guide the workup of children with hearing loss. CONCLUSION: The workup of children with hearing loss can be guided by the recommendations provided herein.

Phenotype of a Belgian Family With 6p25 Deletion Syndrome.

BACKGROUND: The 6p25 deletion syndrome is one of the many syndromes with both hearing impairment as well as vision impairment. However, the audiometric characteristics and radiological findings of patients with 6p25 deletions are only scarcely described in literature. This study focused on characterizing the audiometric and radiological features of a Belgian family with a chromosome 6p25 deletion. OBJECTIVE: To evaluate the hearing impairment, audiometric testing and radiological examination of the temporal bones in 3 family members with a 3.4 Mb deletion in chromosome band 6p25. RESULTS: All 3 family members demonstrated slowly progressive sensorineural or mixed hearing impairment. Radiologic examination revealed thickened and sclerotic stapes in all patients and a minor internal partition type II of the cochlea in 2 patients. CONCLUSION: There is a significant phenotypic variability within and among families with the 6p25 deletion syndrome. A thorough genotype-phenotype correlation is difficult because of the small number of affected patients and the limited clinical data available. More clinical data of families with 6p25 deletions need to be published in order to create a reliable and precise phenotypic characterization. However, our findings can facilitate counseling of hearing impairment caused by 6p25 deletions.

Novel partial duplication of EYA1 causes branchiootic syndrome in a large Brazilian family.

OBJECTIVE: To identify novel genetic causes of syndromic hearing loss in Brazil. DESIGN: To map a candidate chromosomal region through linkage studies in an extensive Brazilian family and identify novel pathogenic variants using sequencing and array-CGH. STUDY SAMPLE: Brazilian pedigree with individuals affected by BO syndrome characterized by deafness and malformations of outer, middle and inner ear, auricular and cervical fistulae, but no renal abnormalities. RESULTS: Whole genome microarray-SNP scanning on samples of 11 affected individuals detected a multipoint Lod score of 2.6 in the EYA1 gene region (chromosome 8). Sequencing of EYA1 in affected patients did not reveal pathogenic mutations. However, oligonucleotide-array-CGH detected a duplication of 71.8Kb involving exons 4 to 10 of EYA1 (heterozygous state). Real-time-PCR confirmed the duplication in fourteen of fifteen affected individuals and absence in 13 unaffected individuals. The exception involved a consanguineous parentage and was assumed to involve a different genetic mechanism. CONCLUSIONS: Our findings implicate this EYA1 partial duplication segregating with BO phenotype in a Brazilian pedigree and is the first description of a large duplication leading to the BOR/BO syndrome.

FGF23 deficiency leads to mixed hearing loss and middle ear malformation in mice.

Fibroblast growth factor 23 (FGF23) is a circulating hormone important in phosphate homeostasis. Abnormal serum levels of FGF23 result in systemic pathologies in humans and mice, including renal phosphate wasting diseases and hyperphosphatemia. We sought to uncover the role FGF23 plays in the auditory system due to shared molecular mechanisms and genetic pathways between ear and kidney development, the critical roles multiple FGFs play in auditory development and the known hearing phenotype in mice deficient in klotho (KL), a critical co-factor for FGF23 signaling. Using functional assessments of hearing, we demonstrate that Fgf[Formula: see text] mice are profoundly deaf. Fgf[Formula: see text] mice have moderate hearing loss above 20 kHz, consistent with mixed conductive and sensorineural pathology of both middle and inner ear origin. Histology and high-voltage X-ray computed tomography of Fgf[Formula: see text] mice demonstrate dysplastic bulla and ossicles; Fgf[Formula: see text] mice have near-normal morphology. The cochleae of mutant mice appear nearly normal on gross and microscopic inspection. In wild type mice, FGF23 is ubiquitously expressed throughout the cochlea. Measurements from Fgf[Formula: see text] mice do not match the auditory phenotype of Kl-/- mice, suggesting that loss of FGF23 activity impacts the auditory system via mechanisms at least partially independent of KL. Given the extensive middle ear malformations and the overlap of initiation of FGF23 activity and Eustachian tube development, this work suggests a possible role for FGF23 in otitis media.

X-linked hearing loss: two gene mutation examples provide generalizable implications for clinical care.

PURPOSE: To describe the inheritance patterns and auditory phenotype features of 3 Canadian families with mutations in 2 X-linked "deafness" genes (DFNX). METHOD: Audiological, medical, and family histories were collected and family members interviewed to compare hearing thresholds and case histories between cases with mutations in SMPX versus POU3F4. RESULTS: The family pedigrees reveal characteristic X-linked inheritance patterns. Phenotypic features associated with the SMPX (DFNX4) mutation include early onset in males with rapid progression from mild and flat to sloping sensorineural loss, with highly variable onset and hearing loss severity in females. In contrast, phenotypic features associated with the POU3F4 (DFNX2) mutation are characterized by an early onset, mixed hearing loss with fluctuation in males, and a normal hearing phenotype reported for females. CONCLUSIONS: The study shows how this unique inheritance pattern and both gender and mutation-specific phenotype variations can alert audiologists to the presence of X-linked genetic etiologies in their clinical practice. By incorporating this knowledge into clinical decision making, audiologists can facilitate the early identification of X-linked hearing loss and contribute to the effective team management of affected families.

Audiological and radiological characteristics of a family with T961G mitochondrial mutation.

OBJECTIVE: The aim of this study was to describe audiological and radiological characteristics, and other secondary aspects, in a family carrying a T961G mutation in the 12S rRNA mitochondrial gene. DESIGN: Case report. STUDY SAMPLE: Six members of a family participated in an audiological evaluation that included pure-tone audiometry, immittance tests, auditory brainstem responses (ABR), and otoacoustic emissions (OAE). The radiological evaluation was conducted through temporal bone CT scans using a Toshiba 16 channels Aquilon Spirale. Neuropsychiatric evaluation was also administered. RESULTS: Three participants were diagnosed with severe sensorineural hearing loss of cochlear origin and cochlear malformations visible in CT scans. One participant had a mild mixed-hearing loss and no cochlear malformations. Two participants had normal audiological and radiological findings. CONCLUSIONS: We believe our study can provide helpful insight on the clinical findings of a rare mutation, of which few data have been presented in literature.

GJB2 (Connexin-26) mutations are not frequent among hearing impaired patients in east Greenland.

OBJECTIVE: Investigate genetic causes of HI among the Inuit populations in the Arctic with a high prevalence of hearing impairment (HI). DESIGN: A cross-sectional survey with population-based controls. STUDY SAMPLE: Forty-five patients, with sensorineural or mixed HI and an available blood sample for GJB2 sequencing from DNA, were selected from 166 east Greenlanders by specialist audiology examination, including pure-tone air and bone conduction audiometry from 125 Hz to 8000 Hz. Controls were 108 east- and 109 west-Greenlanders. RESULTS: Forty-five patients with HI were included, 24 males and 21 females. Median age was 35 years (range: 5-76). The c.35delG allele frequency was 3.3%. One patient, homozygous for the c.35delG GJB2 mutation, had bilateral congenital profound HI. Another with mixed HI was heterozygous for the same mutation. Three were heterozygous for the p.V27I variant and one was heterozygous for the p.V153I variant. The frequency of the c.35delG mutation in the controls varied between 0.5% in west Greenland to 2.3% in east Greenland. CONCLUSION: The c.35delG GJB2 mutation occurs in Greenland with low frequency. We conclude the main causes behind the prevalence of HI in this population are chronic otitis media, noise traumas, and/or unidentified genetic causes.

Temporal bone abnormalities in children with GJB2 mutations.

OBJECTIVES: To determine the incidence of temporal bone abnormalities in children with sensorineural hearing loss (SNHL) and pathogenic biallelic GJB2 mutations. STUDY DESIGN: Retrospective analysis of a large cohort of pediatric patients with biallelic GJB2 mutations and SNHL (observational case series). METHODS: Blinded review of all available temporal bone computed tomographic (CT) and magnetic resonance imaging (MRI) studies in this cohort. RESULTS: Out of 158 patients with biallelic GJB2 mutations, 113 had CT and/or MRI studies available for review. Definite, although generally subtle, inner ear abnormalities were present in 12/113. There were malformations of the semicircular canals (SCC) in 4/12, of the internal auditory canal in 2/12, of the cochlear nerve canal (CNC) in 6, and unilateral cochlear malformation in 1/12. MRI in 1/5 showed mildly hypoplastic cochlear nerve. There was no correlation between SNHL severity and presence/absence/type of malformations or genotype. CONCLUSIONS: Our study of 113 biallelic GJB2 patients with SNHL and temporal bone imaging is the largest study to date. We found only 10% had any abnormalities, most subtle, and none had EVA. Additionally, there was no correlation between SNHL severity and presence/absence/type of malformations or genotype. Disparities between our group and previous reports may be due to differences in degree of hearing loss, types of mutations, populations studied, and radiologic factors for both image acquisition and interpretation.

Pendred syndrome in Tunisia.

OBJECTIVES: We report a clinical and genetic study of three consanguineous Tunisian families affected by Pendred syndrome. PATIENTS AND METHODS: Three families from the south of Tunisia were identified as affected by Pendred syndrome. The patients and their families underwent ENT and general examination and audiovestibular and radiological tests. Molecular DNA analysis was performed by the Sfax Human Molecular Genetics Department. RESULTS: Forty-three patients (mean age: 21 years [2-60 years]) were affected. Tonal audiometry showed bilateral sensorineural hearing loss in 87.5% of cases, and mixed hearing loss in 12.5% with bilateral high frequency sensorineural hearing loss and conductive hearing loss at lower frequencies. Deafness was severe in 21% and profound in 79% of cases. Thyroid goiter was found in 46.5% of cases. Inner ear CT scan found enlarged bilateral vestibular aqueducts in all cases. Hormone analysis was normal and perchlorate test negative in all cases. A single Pendred syndrome (PDS) gene mutation, L445W, was found. DISCUSSION: Pendred syndrome is the most frequent congenital deafness syndrome. It is characterized by great intrafamilial phenotype variability.

Middle ear implant for mixed hearing loss with malformation in a 9-year-old child.

OBJECTIVE: The aim was to report the results of the first case in France of pediatric auditory rehabilitation with a middle ear implant and to discuss the putative indications with this new therapeutic option in children. PATIENT AND METHODS: A prospective study over 18 months on clinical and audiometric results after a middle ear implantation with a Vibrant Med-El(R) implant in a 9-year-old child with mixed hearing loss. RESULTS: Postoperative unaided pure tone audiometry (PTA) was unchanged by the surgical procedure. After 18 months of implant use, the mean PTA loss in free-field warble tone audiometry was 33.75 dB and the intelligibility threshold was 30 dB. After 18 months of follow-up, the intelligibility threshold was improved by 25 dB in comparison with the preoperative results with two hearing aids. The implant worked perfectly well and the child did not show any complication during this period. CONCLUSION: The reliability of the implant and the quality of the auditory results obtained in this case and in a limited number of cases in the world make the Vibrant Med-El(R) a new therapeutic option in hearing loss in children with bilateral auricular atresia.

Hearing loss in Pompe disease revisited: results from a study of 24 children.

Little information is available regarding the auditory function in Pompe patients. Hearing loss has been reported in classic infantile patients, but it is still unknown whether central nervous system involvement interferes with auditory function and whether enzyme replacement therapy can improve hearing. Auditory function has not been studied in children with milder forms of the disease. We analyzed repetitive auditory brainstem response measurements and pure tone audiometry in 24 children with Pompe disease. Only 1 of 13 patients with milder phenotypes showed recurrent conductive hearing loss, while 10 out of 11 classic infantile patients had sensorineural hearing defects. These patients also had a high prevalence of conductive hearing loss. Five patients showed evidence of mild retrocochlear pathology, suggestive of glycogen accumulation in the central nervous system. Hearing loss persisted during therapy in all patients. The results emphasize the need for careful monitoring of auditory function in classic infantile Pompe patients, and for early implementation of hearing aids to protect speech and language development.

Saethre-Chotzen syndrome, Pro136His TWIST mutation, hearing loss, and external and middle ear structural anomalies: report on a Brazilian family.

OBJECTIVE: To describe the clinical, speech, hearing, and imaging findings in three members of a Brazilian family with Saethre-Chotzen syndrome (SCS) who presented some unusual characteristics within the spectrum of the syndrome. DESIGN: Clinical evaluation was performed by a multidisciplinary team. Direct sequencing of the polymerase chain reaction-amplified coding region of the TWIST1 gene, routine and electrophysiological hearing evaluation, speech evaluation, and imaging studies through computed tomography (CT) scan and magnetic resonance imaging (MRI) were performed. RESULTS: TWIST1 gene analysis revealed a Pro136His mutation in all patients. Hearing evaluation showed peripherial and mixed hearing loss in two of the patients, one of them with severe unilateral microtia. Computed tomography scan showed structural middle ear anomalies, and MRI showed distortion of the skull contour as well as some of the brain structures. CONCLUSIONS: We report a previously undescribed TWIST1 gene mutation in patients with SCS. There is evidence that indicates hearing loss (conductive and mixed) can be related both with middle ear (microtia, high jugular bulb, and enlarged vestibules) as well as with brain stem anomalies. Here we discuss the relationship between the gene mutation and the clinical, imaging, speech, and hearing findings.

How to prevent a stapes gusher.

A stapes gusher is the result of a congenital inner ear anomaly showing at tone audiometry a conductive or mixed hearing loss. The conductive part of the hearing loss could lead to the thought to explore the middle ear. The congenital origin should lead to a high resolution. CT-scanning to evaluate a widening of the internal acoustic canal. Repeated audiometry could show especially a large conductive impairment in the lowest frequencies with a closure of the airbone gap at 2 khz and a high sensorineural high frequency loss at 4 and 8 khz. Contralateral stapedial reflexes may be present. Since the x-recessive mixed deafness syndrome (DFN3) frequently involves males with an early childhood hearing impairment, clinical suspicion should be high. When stapes surgery is considered a precise medical history is essential regarding on the start of the hearing impairment. A continuous suspicion will guide to the audiological, radiological and molecular genetic clues to trace the correct diagnosis before embarking on stapes surgery.

Clinics in diagnostic imaging (111): X-linked congenital mixed deafness syndrome.

Two siblings, boys aged five and six years old, presented with mixed hearing loss. Computed tomography of the temporal bones showed bulbous dilatation of the internal auditory canals and incomplete separation with the basal turn of the cochlear, consistent with the diagnosis of X-linked congenital progressive mixed deafness syndrome. The diagnosis and management of this rare condition is discussed.

Hereditary bilateral conductive hearing loss caused by total loss of ossicles: a report of familial expansile osteolysis.

OBJECTIVE: The objective of this study was to report on three members of a family with familial expansile osteolysis; the important point about these patients was that none of them had middle-ear ossicles. STUDY DESIGN AND SUBJECTS: A retrospective case review including three cases with familial expansile osteolysis. SETTING: Department of Otolaryngology in a tertiary referral center. INTERVENTIONS: Each patient underwent computerized tomography of the temporal bone in the coronal view, audiometric and tympanometric evaluations, biochemical investigation, whole body isotope scans by Tc-99 mMDP and X-ray. Also the patients' pedigree was studied. Two of the patients had exploratory middle-ear surgery as well. RESULTS: The temporal-bone computed-tomography scan in the coronal view of all three patients and also exploratory middle-ear surgery, which was done on two of the patients, showed no ossicles in the middle ear of either ear in all three cases. This feature hadn't been reported in previous studies. Hearing loss was revealed in the medical histories since childhood. Audiometry indicated mild to moderate conductive and mixed hearing loss and also an AD-type tympanogram pattern along with an absence of acoustic reflexes in both ears of the cases. Both serum alkaline phosphatase and hydroxyproline levels were elevated. There was an increase in uptake and activity at multiple foci of the whole skeleton. No improvement in hearing thresholds was obtained after reconstruction of the middle ear. CONCLUSION: The total absence of middle-ear ossicles can probably be regarded as a new symptom in some patients with familial expansile osteolysis. Common ossiculoplasty for improving the hearing thresholds in this condition may be unsuccessful; therefore, both surgeons and patients must be completely aware of the contingent undesirable results.

Clinical genetic study of 144 patients with nonsyndromic hearing loss.

Hearing loss constitutes an important category of congenital defects that can be isolated or part of the phenotypic spectrum of several syndromes. A clinical genetic study was performed on a sample of 144 patients with nonsyndromic hearing loss, establishing the sex distribution, type, degree, symmetry, laterality, progression, etiology, and, when possible, inheritance pattern.