Twelve years of neonatal hearing screening: audiological and etiological results.

PURPOSE: Most developed countries have implemented some form of universal newborn hearing screening program. Early identification and rehabilitation of congenital hearing loss is important in functional outcome, and the need to identify the cause of hearing impairment has become clear. We aimed to evaluate audiological and etiological outcomes in a large group of patients with failed neonatal hearing screening. METHODS: We performed a retrospective chart analysis of patients who were referred to our tertiary referral center after failing neonatal hearing screening during a 12-year period (2007-2019). Screening was based on automated auditory brainstem response (AABR) or a combined approach of AABR and auditory steady-state response (ASSR) with chirp stimulus. Extensive audiometric testing was performed to confirm and determine the type and degree of hearing loss. In case of permanent hearing loss, a standardized etiological protocol was followed to determine the cause. RESULTS: Of the 802 referred newborns, hearing loss was confirmed by diagnostic ABR in 78%. Main causes of hearing loss included otitis media with effusion (56%, higher in patients screened by AABR/ASSR compared to AABR), a genetic disorder (12%), congenital cytomegalovirus infection (cCMV, 5%) and atresia/stenosis of the external ear canal (5%). Of the patients with permanent hearing loss, 15% showed changes in hearing loss severity over time. CONCLUSION: In the majority of newborns referred after failing universal neonatal hearing screening, hearing loss could be confirmed. The leading cause was reversible hearing loss due to otitis media with effusion, but hearing loss proved permanent in about 35% of referred newborns, with genetics as predominant cause. Follow-up of congenital hearing loss patients is important as deterioration as well as improvement was observed over time.

Variants affecting diverse domains of MEPE are associated with two distinct bone disorders, a craniofacial bone defect and otosclerosis.

PURPOSE: To characterize new molecular factors implicated in a hereditary congenital facial paresis (HCFP) family and otosclerosis. METHODS: We performed exome sequencing in a four-generation family presenting nonprogressive HCFP and mixed hearing loss (HL). MEPE was analyzed using either Sanger sequencing or molecular inversion probes combined with massive parallel sequencing in 89 otosclerosis families, 1604 unrelated affected subjects, and 1538 unscreened controls. RESULTS: Exome sequencing in the HCFP family led to the identification of a rare segregating heterozygous frameshift variant p.(Gln425Lysfs*38) in MEPE. As the HL phenotype in this family resembled otosclerosis, we performed variant burden and variance components analyses in a large otosclerosis cohort and demonstrated that nonsense and frameshift MEPE variants were significantly enriched in affected subjects (p = 0.0006-0.0060). CONCLUSION: MEPE exerts its function in bone homeostasis by two domains, an RGD and an acidic serine aspartate-rich MEPE-associated (ASARM) motif inhibiting respectively bone resorption and mineralization. All variants associated with otosclerosis are predicted to result in nonsense mediated decay or an ASARM-and-RGD-truncated MEPE. The HCFP variant is predicted to produce an ASARM-truncated MEPE with an intact RGD motif. This difference in effect on the protein corresponds with the presumed pathophysiology of both diseases, and provides a plausible molecular explanation for the distinct phenotypic outcome.

Auditory phenotype in Stickler syndrome: results of audiometric analysis in 20 patients.

Hearing loss in Stickler syndrome has received little attention due to the often more disabling ocular, orofacial and skeletal manifestations. Estimates suggest a global prevalence of sensorineural hearing loss (SNHL) ranging from 50 % to about 100 % though, depending on the underlying Stickler genotype. By performing extensive audiometric analysis in Stickler patients, we aimed to further elucidate the auditory phenotype. Twenty molecularly confirmed Stickler patients (age 10-62 year), of whom sixteen with type 1 Stickler syndrome (COL2A1 mutation) and four with type 2 Stickler syndrome (COL11A1 mutation) underwent an otological questionnaire, clinical examination, pure tone and speech audiometry, tympanometry and otoacoustic emission testing. Cross-sectional and longitudinal regression analysis of the audiograms was performed to assess progression. In type 1 Stickler syndrome, 75 % demonstrated hearing loss, predominantly in the high frequencies. No significant progression beyond presbyacusis was observed. All type 2 Stickler patients exhibited mild-to-moderate low- and mid-frequency SNHL and moderate-to-severe high-frequency SNHL. In both types, hearing loss was observed in childhood. Otoacoustic emissions were only detectable in 7/40 ears and had very low amplitudes, even in frequency bands with normal hearing on pure tone audiometry. Type 1 Stickler syndrome is characterized by a mild high-frequency SNHL, emerging in childhood and non-progressive. Absent otoacoustic emissions are a frequent finding. Patients with type 2 Stickler syndrome exhibit early-onset moderate SNHL affecting all frequencies with a sloping audiogram. Taking into account the visual impairment in many patients, we recommend regular auditory follow-up in patients with Stickler syndrome, especially in childhood.

Novel pathogenic COL11A1/COL11A2 variants in Stickler syndrome detected by targeted NGS and exome sequencing.

INTRODUCTION: Stickler syndrome is caused by mutations in genes encoding type II and type XI collagens. About 85% of the pathogenic variants is found in COL2A1 (Stickler type 1), whereas a minority of mutations has been reported in COL11A1 (Stickler type 2) and COL11A2 (Stickler type 3). Beside the typical skeletal and orofacial manifestations, ocular anomalies are predominantly present in type 1 and type 2, while hearing loss is more pronounced in type 2 and type 3. METHODS: We performed COL11A1 mutation analysis for 40 type 2 Stickler patients and COL11A2 mutation analysis for five type 3 Stickler patients, previously all COL2A1 mutation-negative, using targeted next-generation sequencing (NGS) whereas whole-exome sequencing (WES) was performed in parallel for two patients. Three patients were analyzed for both genes due to unclear ocular findings. RESULTS: In total 14 COL11A1 and two COL11A2 mutations could be identified, seven of which are novel. Splice site alterations are the most frequent mutation type, followed by glycine substitutions. In addition, six variants of unknown significance (VUS) have been found. Identical mutations and variants were identified with both NGS techniques. CONCLUSION: We expand the mutation spectrum of COL11A1 and COL11A2 in Stickler syndrome patients and show that targeted NGS is an efficient and cost-effective molecular tool in the genetic diagnosis of Stickler syndrome, whereas the more standardized WES might be an alternative approach.

Risk Factors for Hearing Loss at Birth in Newborns With Congenital Cytomegalovirus Infection.

Importance: With a prevalence between 0.2% and 6.1% of all live births, congenital cytomegalovirus (cCMV) infection is a major cause of congenital nonhereditary sensorineural hearing loss. Despite the large amount of research on cCMV-related hearing loss, it is still unclear which newborns are at risk of hearing loss. Objective: To identify independent risk factors for cCMV-related congenital hearing loss and predictors of hearing loss severity at birth. Design, Setting, and Participants: This cross-sectional study of newborns with cCMV infection used data included in the Flemish CMV registry that was collected from 6 secondary and tertiary hospitals in Flanders, Belgium, over 15 years (January 1, 2007, to February 7, 2022). Data were analyzed March 3 to October 19, 2022. Patients were included in the study after confirmed diagnosis of cCMV infection and known hearing status at birth. Patients who presented with other possible causes of sensorineural hearing loss were excluded. Main Outcomes and Measures: Primary outcome was hearing status at birth. Clinical, neurological, and laboratory findings along with the timing of seroconversion and blood viral load were separately considered as risk factors. Binary logistic regression was performed to identify independent risk factors for congenital hearing loss in newborns with cCMV. Effect sizes were measured using Hedges g, odds ratio, or Cramer V. Results: Of the 1033 newborns included in the study (553 of 1024 [54.0%] boys), 416 (40.3%) were diagnosed with symptomatic cCMV infection and 617 (59.7%) with asymptomatic cCMV infection. A total of 15.4% of the patients (n = 159) presented with congenital hearing loss; half of them (n = 80 [50.3%]) had isolated hearing loss. The regression model revealed 3 independent risk factors for congenital hearing loss: petechiae at birth (adjusted odds ratio [aOR], 6.7; 95% CI, 1.9-23.9), periventricular cysts on magnetic resonance imaging (MRI; aOR, 4.6; 95% CI, 1.5-14.1), and seroconversion in the first trimester (aOR, 3.1; 95% CI, 1.1-9.3). Lower viral loads were seen in patients with normal hearing compared with those with congenital hearing loss (median [IQR] viral load, 447.0 [39.3-2345.8] copies per milliliter of sample [copies/mL] vs 1349.5 [234.3-14 393.0] copies/mL; median difference, -397.0 [95% CI, -5058.0 to 174.0] copies/mL). Conclusions and Relevance: Findings of this cross-sectional study suggest that newborns with cCMV infection and petechiae at birth, periventricular cysts on MRI, or a seroconversion in the first trimester had a higher risk of congenital hearing loss. Clinicians may use these risk factors to counsel parents in the prenatal and postnatal periods about the risk of congenital hearing loss. Moreover, linking clinical features to hearing loss may provide new insights into the pathogenesis of cCMV-related hearing loss. The importance of viral load as a risk factor for congenital hearing loss remains unclear.

Stapes surgery in osteogenesis imperfecta: retrospective analysis of 34 operated ears.

Intraoperative findings of stapes surgery in 34 ears from 22 patients with genetically confirmed osteogenesis imperfecta (OI) are reported, as well as the audiometric results after the longest postoperative follow-up published to date. Twenty-nine out of 34 ears underwent primary stapes surgery and 5 ears revision surgery. Postoperative audiometric follow-up ranged from 6 months to 37 years. Stapes footplates were fixed in all ears. Additionally, footplates were thickened or fragile, stapes crura atrophic or fractured, and middle ear mucosae thickened or hypervascularized. Short-term postoperative audiometry revealed improved hearing and reduced air-bone gaps in 28/29 primary operated ears and in all revision cases. In the 22 ears with long-term postoperative follow-up (mean duration: 16 years), hearing gain was still significant at the latest audiometric evaluation. Independently of the patients being diagnosed with OI type I or IV and independently of the underlying OI genotype, beneficial results are obtained in the majority of OI patients undergoing primary or revision stapes surgery for reduction of conductive hearing loss components caused by stapes footplate fixation. Despite the progressive course of the concomitant sensorineural component, hearing gain remains beneficial over several decades.

Hearing Loss in Stickler Syndrome: An Update.

Stickler syndrome is a connective tissue disorder characterized by ocular, skeletal, orofacial and auditory manifestations. Its main symptoms are high myopia, retinal detachment, joint hypermobility, early osteoarthritis, cleft palate, midfacial hypoplasia, micrognathia and hearing loss. Large phenotypical variability is apparent and partly explained by the underlying genetic heterogeneity, including collagen genes (COL2A1, COL11A1, COL11A2, COL9A1, COL9A2, COL9A3) and non-collagen genes (BMP4, LRP2, LOXL3). The most frequent type of Stickler syndrome (COL2A1) is characterized by a rather mild high-frequency sensorineural hearing loss in about half of the patients. COL11A1- and COL11A2-related Stickler syndrome results in more frequent hearing loss, being moderate and involving all frequencies. Hearing loss in the rarer types of Stickler syndrome depends on the gene expression in the cochlea, with moderate to severe downsloping hearing loss for Stickler syndrome caused by biallelic type IX collagen gene mutations and none or mild hearing loss for the non-collagen genes. Inherent to the orofacial manifestations, middle ear problems and temporary conductive hearing loss, especially at young age, are also prevalent. Consequently, hearing loss should be actively sought for and adequately treated in Stickler syndrome patients given its high prevalence and the concomitant visual impairment in most patients.

Congenital Unilateral Hearing Loss: Characteristics and Etiological Analysis in 121 Patients.

OBJECTIVE: To describe the characteristics and etiological analysis in patients with congenital unilateral hearing loss. STUDY DESIGN: Retrospective cohort analysis. SETTING: Tertiary referral center. PATIENTS: Children with permanent congenital unilateral hearing loss born between 2007 and 2018. Patients were referred after universal newborn hearing screening or by a colleague to confirm the diagnosis and perform etiological examinations. MAIN OUTCOME MEASURES: Hearing loss type, severity, and evolution linked with the results of etiological testing. RESULTS: In the 121 included children, aural atresia is the leading cause of congenital unilateral hearing loss (32%), followed by structural anomalies (19%) and cCMV (13%), whereas 24% remained idiopathic after etiological work-up. Severity is mainly moderately severe (33% with 56-70 dB hearing loss, majority aural atresia) or profound (31% with > 90 dB hearing loss, predominantly cochlear nerve deficiency). Syndromic features were present in 26%. Although discussed with all parents, only 26% of the children regularly used hearing amplification. CONCLUSIONS: Congenital conductive unilateral hearing loss is mainly caused by aural atresia, which proportion in congenital unilateral hearing loss proved higher than previously reported. Cochlear nerve deficiency and cCMV are the predominant etiologies of congenital unilateral sensorineural hearing loss. Etiological work-up in affected patients is mandatory as it might impact the approach, and syndromic features should be actively searched for.

Speech outcome regarding overall intelligibility, articulation, resonance and voice in Flemish children a year after pharyngeal flap surgery. A pilot study.

OBJECTIVE: The main purpose of this study is to determine the treatment effectiveness of pharyngeal flap surgery by measuring speech outcome 1 year after surgery. The authors hypothesized that flap surgery is an effective technique for velopharyngeal inadequacy resulting in improved intelligibility, decreased hypernasality and nasalance scores and normal voice characteristics. PATIENTS AND METHODS: Objective (Nasometer, Dysphonia Severity Index) as well as subjective (perceptual evaluations) assessment techniques were performed in 7 subjects. Speech evaluations were performed 1 year after flap surgery and comparison was made between the speech results of the preoperative condition (1 week before surgery) and the first postoperative condition (6 weeks after surgery). RESULTS: After pharyngeal flap surgery there was improved though still slightly impaired intelligibility, with normal nasality, normal nasalance values for standard Flemish speech and normal voice characteristics. The normal nasality and nasalance values were not present in the preoperative condition. Persistence of the incorrect production of the thrill sound /r/ and the fricatives /s/ and /sch/ were observed. CONCLUSION: It is likely that the slightly impaired speech intelligibility is determined by the presence of persistent articulation disorders.

The phenotype of the first otosclerosis family linked to OTSC5.

OBJECTIVE: To report the audiometric and radiologic findings in the first otosclerosis family linked to OTSC5. STUDY DESIGN: A clinical investigation of a family linked to OTSC5, including analyses of audiometric data and of high-resolution computed tomography (CT) images of the temporal bones from genetically affected family members. SETTING: Tertiary referral center. PATIENTS: Family members from a four-generation pedigree with otosclerosis segregating as an autosomal dominant trait. MAIN OUTCOME MEASURE(S): Pre-surgery pure tone audiometric data. Classification of otosclerotic foci on high-resolution spiral CT images of the temporal bones of genetically affected individuals. RESULTS: Audiometric data showed a considerable degree of phenotypic variability. Cross-sectional regression analysis did not disclose any clear age dependence of threshold-related data. Systematic differences between mean parameter values relating to the thresholds in the best or the worst ear were found. High-resolution CT images revealed a fenestral otosclerotic focus in seven of nine (78%) clinically affected individuals and cochlear foci in one of these seven patients. CONCLUSION: The phenotype of OTSC5 seems to be variable. Additional long-term audiometric data are needed to construct age-related typical audiograms, which may also facilitate the comparison between phenotypes of the different otosclerosis loci. The detection rate of otospongiotic foci in our study group is similar or lower compared with previous reports on CT data in consecutive otosclerosis patients who had stapes replacing surgery.

Cephalometrics in Stickler syndrome: Objectification of the typical facial appearance.

INTRODUCTION: Stickler syndrome is a connective tissue disorder characterized by orofacial, ocular, skeletal and auditory symptoms. The orofacial phenotype mainly consists of midfacial hypoplasia, micrognathia and cleft palate. Large phenotypic variability is evident though. Few studies have tried to substantiate the typical facial appearance in Stickler syndrome patients. METHODS: Molecularly confirmed Stickler patients were invited to undergo cephalometric analysis based on a lateral radiograph in standardized conditions. Angular and linear measurements were performed according to Steiner's and Sassouni's analysis and compared with age- and gender-matched reference values. RESULTS: Thirteen patients aged 10-62y were included, twelve of whom had type 1 Stickler syndrome (COL2A1 mutation) and one type 2 Stickler syndrome (COL11A1 mutation). The position of maxilla and mandible relative to the cranial base was not significantly different from the reference population (S-N-A: p = 0.73, S-N-B: p = 0.43). The mandibular plane and y-axis showed an elevated angle with the cranial base in most patients, although not significant for the total group (S-N to Go-Me: p = 0.20, S-N to S-Gn: p = 0.18). Dental analysis was normal, except for a higher overjet value (p = 0.006) and a higher angle between occlusal plane and Frankfort plane (p = 0.022). CONCLUSION: Cephalometric analysis was not able to thoroughly prove the abnormal facial appearance in Stickler syndrome. The majority of patients had normal dentofacial proportions. The most frequently observed anomaly in our series is a rather short and posteriorly rotated mandible, but clinical variability is high.

Audiometric, vestibular, and genetic aspects of a DFNA9 family with a G88E COCH mutation.

OBJECTIVES: To perform genetic analysis and to analyze cochleovestibular impairment features in a newly identified Dutch family with nonsyndromic autosomal dominant hearing impairment (DFNA9). STUDY DESIGN: Genetic analysis was performed using microsatellite markers and single nucleotide polymorphisms. Audiometric data were collected and analyzed longitudinally. Results were compared with those obtained in previously identified P51S COCH mutation carriers (n = 74). Special attention was also given to a comparison of age-related features such as progressive hearing loss and vestibular impairment. SETTING: Tertiary referral center. PATIENTS: G88E COCH mutation carriers from a Dutch family. MAIN OUTCOME MEASURES: The study of clinical features of a DFNA9 family carrying a G88E COCH mutation and to compare this to the symptoms of those carrying a P51S/COCH mutation. RESULTS: Pure-tone thresholds, phoneme recognition scores, and vestibular responses of the G88E mutation carriers were essentially similar to those previously established in the P51S mutation carriers. Hearing started to deteriorate in G88E mutation carriers from age 46 to 49 years and onward, whereas deterioration of vestibular function started from approximately age 46 years. In the P51S mutation carriers, vestibular impairment started earlier, at approximately age 34 years. However, the difference in age of onset with the G88E mutation carriers was not significant. Remarkably, the proportion of patients who developed complete vestibular areflexia within the age range of 40 to 56 years was significantly lower for the G88E mutation carriers than for the P51S mutation carriers. CONCLUSION: Apart from a significantly lower frequency of vestibular areflexia between the ages of 40 and 56 years, there are no phenotypic differences between carriers of the G88E and P51S mutations in the COCH gene.

Etiological approach in patients with unidentified hearing loss.

OBJECTIVES: Etiological diagnosis of hearing impairment is of great importance to ensure early and adequate management. Even after thorough history taking, clinical and audiometric evaluation, the cause of hearing loss remains unclear in a majority of patients. Further examinations can imply imaging, ophthalmologic investigations, laboratory tests, electrocardiography and genetic testing. Lately, the latter has taken an increasingly prominent place within this diagnostic work-up. However, clear guidelines about optimal implementation and sequence of these tests are required. METHODS: Records of patients who visited the consultation for otogenetics at Ghent University Hospital (Belgium) during the period 2006-2012 were retrospectively reviewed. In order to optimize the etiological-diagnostic work-up of unidentified hearing loss, application patterns and results of various diagnostic tests, audiometric and etiological data of each patient were collected and analyzed. RESULTS: Data of 191 patients were analyzed. In 81.2% of the patients, a cause of hearing loss could be determined or suspected. In total, 65.4% had a (presumably) genetic etiology, with connexin 26 (GJB2) mutations as the leading cause. Inquiry of risk factors, associated with congenital hearing loss, and pedigree analysis were found to have the highest diagnostic gain (61.3% and 41.8%). Connexin 26 gene mutations were only present in bilateral hearing impairment, whereas CT abnormalities were related to unilateral (P=0.003), profound (P<0.001) hearing loss. An enlarged vestibular aqueduct was present in 42.9% of all CT abnormalities. Ophthalmologic anomalies were detected in 35.7% of the studied patients. CONCLUSIONS: A sequential approach for the etiological diagnosis of unidentified hearing loss could determine or suggest a cause in more than 80% of patients. The approach may vary based on the presenting phenotype.

A mutational hot spot in the KCNQ4 gene responsible for autosomal dominant hearing impairment.

Several different mutations in the KCNQ4 K+ channel gene are responsible for autosomal dominant nonsyndromic hearing impairment (DFNA2). Here we describe two additional families originating from Europe and Japan with a KCNQ4 missense mutation (W276S) that was previously found in one European family. We compared the disease-associated haplotype of the three W276S-bearing families using closely linked microsatellite markers and intragenic single nucleotide polymorphisms. Differences between the haplotypes were found, excluding a single founder mutation for the families. Therefore, the W276S mutation has occurred three times independently, and most likely represents a hot spot for mutation in the KCNQ4 gene.

A Dutch family with hearing loss linked to the DFNA20/26 locus: longitudinal analysis of hearing impairment.

OBJECTIVES: To perform linkage analysis and to outline hearing loss characteristics in a family exhibiting a nonsyndromic, autosomal dominant type of progressive sensorineural hearing loss. DESIGN: Genetic analysis was performed using microsatellite markers. Audiometric data were collected and analyzed longitudinally. Sigmoidal dose-response curves enabled us to perform nonlinear regression analysis per frequency and on phoneme recognition scores. Speech recognition scores were compared with those of DFNA2, DFNA5, DFNA9, and presbyacusis subjects. SUBJECTS: Affected family members of a Dutch family (W99-060). RESULTS: We revealed linkage of hearing loss to the DFNA20/26 locus (maximum logarithm of odds score, 3.1 at theta=0.04) and reduced the critical region from 12 to 9.5 centimorgans. Patients younger than 15 years already showed gently downsloping audiograms. At ages 15 to 20 and 25 to 40 years, hearing loss was profound at 8 kHz and 1 to 4 kHz, respectively. The 0.25- to 0.5-kHz thresholds showed more gradual progression by about 1.5 to 2 dB/y. From about age 40 years onward, hearing was residual. Hearing impairment took a more severe course than in a known DFNA20 family. Score recognition in DFNA20/26 subjects was better than in DFNA9 subjects at any pure-tone average (1-4 kHz) threshold. Compared with subjects having DFNA2 and DFNA5, speech recognition in those with DFNA20/26 scored better at threshold levels below 85 dB hearing level, but worse at levels above 90 dB. Compared with presbyacusis subjects, those with DFNA20/26 scored better in speech recognition at levels below 100 dB and worse at levels above 100 dB. CONCLUSIONS: Autosomal dominant hearing loss is linked to the DFNA20/26 locus in this Dutch family. The critical region is reduced from 12 to 9.5 centimorgans. Phenotypically, patients are more severely affected than those of a known DFNA20 family.

Longitudinal and cross-sectional phenotype analysis in a new, large Dutch DFNA2/KCNQ4 family.

We analyzed hearing thresholds, speech recognition scores, and vestibular responses in 32 affected persons in a large family with DFNA2/KCNQ4-related hearing impairment caused by a W276S missense mutation. Linear regression analysis of individual longitudinal data revealed significant threshold progression (1 dB/y) and offset (at age zero). The mean offset thresholds were 5, 21, 40, 39, 31, and 51 dB hearing level (HL) at 0.25, 0.5, 1, 2, 4, and 8 kHz, respectively. Cross-sectional analysis of last-visit thresholds against age produced less-steep slopes and higher offset thresholds. Nonlinear regression analysis of last-visit phoneme recognition scores against age in 25 cases showed that speech recognition did not deteriorate before the third decade. A hyperactive vestibuloocular reflex was found in 3 of 11 cases: 2 persons were especially susceptible to motion sickness. Persons with this KCNQ4 mutation showed congenital, progressive high-frequency impairment without substantial loss of speech recognition during the first decades of life.

Audiological characteristics of some affected members of a Dutch DFNA13/COL11A2 family.

Members of a Dutch DFNA13/COL11A2 family were evaluated with pure tone audiometry, stapedial reflexes, otoacoustic emissions, loudness scaling, difference limen for frequency, gap detection, and speech perception in quiet and noise. The tone audiometry showed a predominant loss for the low and middle frequencies, with only a few otoacoustic emissions at thresholds better than 25 dB hearing level. The stapedial reflexes appeared elevated, and loudness growth curves were shifted parallel to those for normal-hearing subjects, indicating a shift of the dynamic range toward higher presentation levels. The data for the difference limen for frequency, gap detection, and speech perception in noise fell within the (near-)normal range. Despite elevated thresholds, all suprathreshold functions showed fairly normal properties, suggesting an attenuation of signal energy in the cochlea with limited degradation of the cochlea's signal analyzing capabilities. The effect of DFNA13/COL11A2 may thus be characterized as a cochlear conductive loss.

Congenital conductive hearing loss in dyschondrosteosis.

Conductive hearing loss was detected in a boy with a previous diagnosis of dyschondrosteosis. Dyschondrosteosis is a rare inherited condition characterized by mesomelic dwarfism and Madelung's deformity. The syndrome can be caused by mutations in the SHOX gene, and in that case, the pattern of inheritance is pseudoautosomal dominant. Indeed, SHOX mutation analysis in our patient revealed a deletion. The combination of dyschondrosteosis and conductive hearing loss has been reported in 2 previous cases. In our patient, exploratory tympanotomy revealed ankylosis of the stapes and a malformed incus. A substantial gain in hearing threshold was obtained by a stapedectomy in combination with a malleovestibulopexy.

Further delineation of the DFNA5 phenotype: results of speech recognition tests.

Speech recognition scores were analyzed in 34 carriers of a DFNA5 mutation. Cross-sectional linear regression analysis (last visit, maximum recognition score in %Correct on age or PTA1,2,4 kHz) established onset age (score 90%) at 16 years and onset PTA1,2,4 kHz level (score 90%) at 41 dB hearing level. The deterioration rate was 0.7%/y in the plot of maximum score against age, whereas the deterioration gradient was 0.4%/dB in the plot of maximum score against PTA1,2,4 kHz. Given the previously demonstrated rapid progression of hearing impairment, speech recognition was relatively good: at age 70, the score was still >50%.

Stickler syndrome type I and Stapes ankylosis.

OBJECTIVE: To report a successful stapedectomy for stapedial fixation in a patient with Stickler syndrome type I (COL2A1). SETTING: University Hospital Department for Otology, Pathology, Ophthalmology and Clinical Genetics. STUDY DESIGN: A clinical and genetic evaluation of a mother and daughter focusing mainly on the otological, ophthalmological, histological and genetical aspects. INTERVENTION: A stapedectomy was performed successfully. RESULTS: Hearing impairment improved after stapedectomy. Postoperatively a shift in high-frequency threshold wa seen related to the stapedectomy. A new mutation in COL2A1 gene was dectected. CONCLUSION: Stapedial fixation can be the cause of hearing impairment in Stickler syndrome type I (COL2A1). The hearing impairment can be improved by stapes surgery.