"My Plate is Full": Reasons for Declining a Genetic Evaluation of Hearing Loss.

The aim of this study was to obtain patient and parent perspectives on genetic evaluation of hearing loss, in order to identify motivators, expectations, and barriers. Three focus groups were conducted following a semi-structured discussion guide, led by an independent moderator. Participants were hearing parents of children with permanent hearing loss or deaf adults. Qualitative content analysis was used to develop a codebook and identify major themes and subthemes. Participant views were compared to national guidelines. The 28 participants comprised 23 parents representing 21 unique families and 5 deaf adults. 13/21 families and 0/5 adults reported comorbidities, 4/21 families and 3/5 adults had a positive family history, and 12/21 families versus 0/5 adults had utilized genetics services. A common theme among adults and parents was a curiosity as to the cause of hearing loss. Parents were motivated to detect comorbidities and optimize care for hearing loss. Some parents felt overwhelmed by the hearing loss and unprepared to pursue early genetic evaluation as recommended in guidelines. Several reported positive experiences following genetics consultation, while others reported unease and unmet expectations. Notably, both parents and adults expressed ambivalence regarding the desire for genetic knowledge. Financial concerns and difficulties obtaining a referral were cited as extrinsic barriers. For parents of children with hearing loss, both the presence of comorbidities and a positive family history were drivers of genetics consultation and/or genetic testing. We identified educational opportunities for both patients and providers that would improve informed decision-making and increase access to genetic services. Consideration of the patient/family perspective and their decision-making processes, along with flexibility in the approach to genetics evaluation and its timing, will optimize both the development and implementation of guidelines.

Clinical characterization of novel chromosome 22q13 microdeletions.

INTRODUCTION: The advent of chromosome microarray analysis (CMA) for evaluation of patients with multiple congenital anomalies has made it possible to define chromosomal imbalances with greater precision and resolutions significantly smaller than possible by standard G-banded chromosome analysis. We describe two patients with novel chromosomal anomalies involving chromosome 22q13, a locus also associated with Phelan-McDermid syndrome (PMS). OBJECTIVE: We aim to characterize the novel phenotypic and genotypic findings of two patients with 22q13 microdeletions, distinct from PMS, comparing and contrasting with features of PMS. RESULTS: Case 1 is a 4-year-old boy with global developmental delay, esotropia, moderate aortic root dilation, genu valgum, and in-toeing gait. MRI brain for evaluation of neonatal hypotonia revealed a left cerebellopontine angle arachnoid cyst. He referred on newborn hearing screening, and diagnostic auditory brainstem response (ABR) showed left profound retrocochlear hearing loss. Surgical intervention for the arachnoid cyst was deferred, with spontaneous resolution at age two years without hearing recovery. CMA revealed a novel, de novo 5.1 Mb microdeletion of 22q13.31q13.33 not involving SHANK3, a gene typically deleted in PMS. Case 2 is a 6-year-old girl with some features also seen in patients with PMS but also several atypical features. She has a complex chromosomal rearrangement including a 5.3 Mb 22q13 microdeletion (not including SHANK3) and de novo 2.1 Mb gain of 22q11. CONCLUSION: As diagnostic sensitivity improves, smaller chromosomal imbalances will be detectable related to milder or different phenotypes. We present two patients with novel deletions of chromosome 22q13 associated with multiple congenital anomalies and features distinct from PMS.

Superior Canal Dehiscence Syndrome Affecting 3 Families.

Importance: Superior canal dehiscence syndrome (SCDS) is an increasingly recognized cause of hearing loss and vestibular symptoms, but the etiology of this condition remains unknown. Objective: To describe 7 cases of SCDS across 3 families. Design, Setting, and Participants: This retrospective case series included 7 patients from 3 different families treated at a neurotology clinic at a tertiary academic medical center from 2010 to 2014. Patients were referred by other otolaryngologists or were self-referred. Each patient demonstrated unilateral or bilateral SCDS or near dehiscence. Interventions: Clinical evaluation involved body mass index calculation, audiometry, cervical vestibular evoked myogenic potential testing, electrocochleography, and multiplanar computed tomographic (CT) scan of the temporal bones. Zygosity testing was performed on twin siblings. Main Outcomes and Measures: The diagnosis of SCDS was made if bone was absent over the superior semicircular canal on 2 consecutive CT images, in addition to 1 physiologic sign consistent with labyrinthine dehiscence. Near dehiscence was defined as absent bone on only 1 CT image but with symptoms and at least 1 physiologic sign of labyrinthine dehiscence. Results: A total of 7 patients (5 female and 2 male; age range, 8-49 years) from 3 families underwent evaluation. Family A consisted of 3 adult first-degree relatives, of whom 2 were diagnosed with SCDS and 1 with near dehiscence. Family B included a mother and her child, both of whom were diagnosed with unilateral SCDS. Family C consisted of adult monozygotic twins, each of whom was diagnosed with unilateral SCDS. For all cases, dehiscence was located at the arcuate eminence. Obesity alone did not explain the occurrence of SCDS because 5 of the 7 cases had a body mass index (calculated as weight in kilograms divided by height in meters squared) less than 30.0. Conclusions and Relevance: Superior canal dehiscence syndrome is a rare, often unrecognized condition. This report of 3 multiplex families with SCDS provides evidence in support of a potential genetic contribution to the etiology. Symptomatic first-degree relatives of patients diagnosed with SCDS should be offered evaluation to improve detection of this disorder.

Parent Perception of Newborn Hearing Screening: Results of a US National Survey.

IMPORTANCE: An unacceptably high number of children who do not pass universal newborn hearing screening (UNHS) are lost to follow-up. OBJECTIVES: To provide insight into parent recall of UNHS. DESIGN, SETTING, AND PARTICIPANTS: In this nationally representative cross-sectional survey, 2144 US parent households were surveyed in May 2012 using the Knowledge Panel. Responses of parents whose children were born before vs after UNHS implementation were compared. MAIN OUTCOMES AND MEASURES: Outcome measures included recall of hearing screen at birth, hearing screen results, and recommendations for follow-up. All outcome measures were based on parent recall and report. Descriptive statistics and multiple logistic regression analyses were used. RESULTS: The study participants included 1539 parent households and 605 nonparent households. Of the 1539 parent households surveyed, the mean age of the parents was 38.8 years (range, 18-88 years), the mean age of the children was 10.2 years (range, 0-17 years), and the mean age of children with hearing loss was 12.1 years (range, 0-17 years). A total of 1539 parents (55.8%) were women. Only 62.9% of parents (unweighted n = 950) recalled a newborn hearing screen, and among those children with risk indicators for hearing loss (n = 587), only 68.6% (unweighted n = 385) recalled a hearing screen. Higher parent educational level (odds ratio [OR], 2.27; 95% CI, 1.17-4.41, for some college and OR, 2.41; 95% CI, 1.22-4.78, for a bachelor's degree; P = .03), younger age of the child (OR, 1.16; 95% CI, 1.11-1.23; P < .001), and the presence of any risk indicator for hearing loss (OR, 1.5; 95% CI, 1.13-2.13; P = .007) were associated with parent recall of hearing screen. Reported pass rates were higher than expected. Parent recall of follow-up recommendations was not always consistent with guidelines. CONCLUSIONS AND RELEVANCE: Although this study is inherently limited by recall bias, the findings indicate a lack of parent awareness of UNHS. Changes in the system of reporting UNHS results are necessary to improve parent recall of screen results and improve follow-up for children who do not pass the screen.

Remodeling of the Inner Hair Cell Microtubule Meshwork in a Mouse Model of Auditory Neuropathy AUNA1.

Auditory neuropathy 1 (AUNA1) is a form of human deafness resulting from a point mutation in the 5' untranslated region of the Diaphanous homolog 3 (DIAPH3) gene. Notably, the DIAPH3 mutation leads to the overexpression of the DIAPH3 protein, a formin family member involved in cytoskeleton dynamics. Through study of diap3-overexpressing transgenic (Tg) mice, we examine in further detail the anatomical, functional, and molecular mechanisms underlying AUNA1. We identify diap3 as a component of the hair cells apical pole in wild-type mice. In the diap3-overexpressing Tg mice, which show a progressive threshold shift associated with a defect in inner hair cells (IHCs), the neurotransmitter release and potassium conductances are not affected. Strikingly, the overexpression of diap3 results in a selective and early-onset alteration of the IHC cuticular plate. Molecular dissection of the apical components revealed that the microtubule meshwork first undergoes aberrant targeting into the cuticular plate of Tg IHCs, followed by collapse of the stereociliary bundle, with eventual loss of the IHC capacity to transmit incoming auditory stimuli.

Temporal Bone Histopathology in NOG-Symphalangism Spectrum Disorder.

OBJECTIVE: To describe the human temporal bone histopathology in NOG-related symphalangism spectrum disorder, a spectrum of congenital stape fixation syndromes caused by mutations in the NOG gene. To discuss implications for clinical management. PATIENT: A patient with a mutation in the NOG gene. INTERVENTION(S): Removal of temporal bones, postmortem temporal bone computed tomography, histologic processing, and review of temporal bones. MAIN OUTCOME MEASURE(S): Temporal bone histopathology and correlation with clinical, genetic, audiologic, and radiologic evaluations. RESULTS: Both temporal bones demonstrated fixation of the stapes footplate to the otic capsule because of a circumferential bridge of calcified cartilage. In the right ear (unoperated), there was no additional abnormality of the ossicles or ossicular joints. In the left ear, fenestrations of the stapes footplate and the lateral semicircular canal were seen, consistent with a history of stapedectomy and fenestration procedure. Severe loss of spiral ganglion neurons throughout the left cochlea accounted for the profound sensorineural hearing loss; there was a normal number of spiral ganglion neurons in the right ear. In both ears, the cochleae demonstrated grossly preserved organs of Corti. CONCLUSION: The temporal bone pathologic correlate for conductive hearing loss in this patient with a NOG mutation was circumferentially calcified cartilage bridging the stapedovestibular joint space. The temporal bone histopathology findings suggest that conductive hearing loss related to NOG mutation should be improved after stapedectomy; however, care must be taken in extrapolating to all patients with NOG mutations because there may be variability in the pathology, especially given the variability of NOG spectrum disorders.

Infantile Frey's syndrome.

Frey's syndrome in children is rare and often erroneously attributed to food allergy. Here we describe a case of Frey's syndrome in an infant and provide a review of the literature. Awareness of this condition is important for the Otolaryngologist in order to avoid unnecessary medical costs and procedures and provide reassurance to both parents and primary care providers in the setting of this benign condition.

Validity, discriminative ability, and reliability of the hearing-related quality of life questionnaire for adolescents.

OBJECTIVES/HYPOTHESIS: The prevalence of hearing loss (HL) in adolescents has grown over the past decade, but hearing-related quality of life (QOL) has not been well-measured. We sought to develop a reliable, valid measure of hearing-related QOL for adolescents and the Hearing Environments And Reflection on Quality of Life (HEAR-QL). STUDY DESIGN: Multisite observational study. METHODS: Adolescents with HL and siblings without HL were recruited from five centers. Participants completed the HEAR-QL and validated questionnaires measuring generic pediatric QOL (PedsQL), depression and anxiety (RCADS-25), and hearing-related QOL for adults (HHIA) to determine construct and discriminant validity. Participants completed the HEAR-QL 2 weeks later for test-retest reliability. We used exploratory principal components analysis to determine the HEAR-QL factor structure and measured reliability. Sensitivity and specificity of the HEAR-QL, PedsQL, HHIA, and RCADS-25 were assessed. We compared scores on all surveys between those with normal hearing, unilateral, and bilateral HL. RESULTS: A total of 233 adolescents (13-18 years old) participated: 179 with HL, 54 without HL. The original 45-item HEAR-QL was shortened to 28 items after determining factor structure. The resulting HEAR-QL-28 demonstrated excellent reliability (Cronbach's alpha = 0.95) and construct validity (HHIA: r = .845, PedsQL: r = .587; RCADS-25: r = .433). The HEAR-QL-28 displayed excellent discriminant validity, with higher area under the curve (0.932) than the PedsQL (0.597) or RCADS-25 (0.529). Teens with bilateral HL using hearing devices reported worse QOL on the HEAR-QL and HHIA than peers with HL not using devices. CONCLUSIONS: The HEAR-QL is a sensitive, reliable, and valid measure of hearing-related QOL for adolescents. LEVEL OF EVIDENCE: 2b.

Novel DICER1 mutation as cause of multinodular goiter in children.

BACKGROUND: The aim of this report was to present a rare case of an adolescent with multinodular goiter (MNG) found to have a DICER1 mutation. METHODS AND RESULTS: The methodology includes a presentation and discussion of a chart review including endocrine hormone tests, thyroid ultrasound, and genetic testing for DICER1. A 12-year-old girl presented with a diffusely enlarged thyroid gland. Family history revealed an older sister with a history of bilateral ovarian Sertoli-Leydig cell tumors and MNG. Thyroid function tests were normal. Serial thyroid ultrasounds showed enlarging multiple bilateral nodules. Fine-needle aspiration suggested MNG. Genetic testing revealed a novel heterozygous premature termination mutation (c.1525C>T p.R509X) in the DICER1 gene. CONCLUSIONS: Thyroid nodules are rare in children but carry a higher risk for malignancy. It is essential to inquire about family history and refer for genetic evaluation with a family history of MNG. In patients with DICER1 mutations, tumor surveillance is critical due to the increased risk of multiple tumors, including ovarian tumors and pleuropulmonary blastoma.

Diaphanous homolog 3 (Diap3) overexpression causes progressive hearing loss and inner hair cell defects in a transgenic mouse model of human deafness.

We previously demonstrated that a mutation in the 5' untranslated region of Diaphanous homolog 3 (DIAPH3) results in 2 to 3-fold overexpression of the gene, leading to a form of delayed onset, progressive human deafness known as AUNA1 (auditory neuropathy, nonsyndromic, autosomal dominant, 1). To investigate the mechanism of deafness, we generated two lines of transgenic mice overexpressing Diap3, the murine ortholog of DIAPH3, on an FVB/NJ background. Line 771 exhibits a relatively mild 20 dB hearing loss at 12 kHz at 4 and 8 weeks of age, progressing to 40 dB and 60 dB losses at 16 and 24 weeks, respectively, at 12 and 24 kHz. Line 924 shows no hearing loss at 4 or 8 weeks, but manifests 35 and 50 dB threshold shifts at 16 and 24 weeks, respectively, at both 12 and 24 kHz. Notably, mice from the two transgenic lines retain distortion product otoacoustic emissions, indicative of normal cochlear outer hair cell (OHC) function despite elevation of auditory thresholds. Scanning electron microscopy of the organ of Corti demonstrates striking anomalies of the inner hair cell (IHC) stereocilia, while OHCs are essentially intact. Over time, IHCs of both lines develop elongated stereocilia that appear fused with neighboring stereocilia, in parallel to the time course of hearing loss in each line. Furthermore, we observe significant reduction in the number of IHC ribbon synapses over 24 weeks in both lines, although this reduction does not correlate temporally with onset and progression of hearing loss or stereociliary anomalies. In summary, overexpression of wild-type Diap3 in two lines of transgenic mice results in hearing loss that recapitulates human AUNA1 deafness. These findings suggest an essential role of Diap3 in regulating assembly and/or maintenance of actin filaments in IHC stereocilia, as well as a potential role at the IHC ribbon synapse.

Residual thyroid tissue after thyroidectomy in a patient with TSH receptor-activating mutation presenting as a neck mass.

BACKGROUND: Activating mutations of the TSH receptor (TSHR) are rare, with few reported cases of long-term follow-up. CASE: We present a follow-up report on a patient with neonatal thyrotoxicosis known to have a rare activating mutation of the TSHR, a heterozygous substitution in exon 10 (p.Ile568Thr). Initial treatment included total thyroidectomy at age 2 ½ years, resulting in iatrogenic hypothyroidism and hypoparathyroidism. The patient was treated with levothyroxine replacement to maintain TSH levels within normal range, as well as calcitriol and calcium carbonate to treat postsurgical hypoparathyroidism. However, 4 years later, while euthyroid, he developed a palpable 1-cm midline neck mass. METHODS AND RESULTS: Functional imaging with 123-I thyroid scan demonstrated active thyroid tissue within the thyroglossal duct remnant and in the tracheoesophageal groove. Surgical removal of the neck mass revealed cytologically bland thyroid follicular cells. CONCLUSION: These findings suggest that even after total thyroidectomy, patients with TSHR-activating mutations are at risk to develop significant quantities of functional thyroid tissue related to the hypertrophy of residual foci in the thyroid bed and in the thyroglossal duct remnant. These residual foci may enlarge and secrete thyroid hormones autonomously, decreasing the patient's levothyroxine requirement. Surveillance with serial physical examination and biochemical monitoring is recommended; suspicious findings can be further evaluated with functional thyroid imaging (99-m technetium or radioiodine 123-I thyroid scans) to adequately identify residual foci of thyroid tissue, which may require further treatment with surgical excision or radioablation.

Ossifying lipoma of c1-c2 in an adolescent.

BACKGROUND: Ossifying lipomas, characterized by their independence of bony connection to the skeleton, are extremely rare benign neoplasms. They have primarily been described in adults older than 50 years of age and occur in the head and neck region. The etiology is unknown. Excision is the preferred treatment. The objective of this study is to report the case of a rare ossifying lipoma immediately anterior to C1 to C2, requiring a transoral approach for excision. METHODS: The case of an adolescent with a retropharyngeal mass is described. RESULTS: A 15-year-old female patient presented with an asymptomatic parapharyngeal mass detected on routine physical examination. Computed tomography and magnetic resonance imaging noted a calcified, left-sided, parapharyngeal mass, approximately 3×2×2 cm, anterior to C1 and C2, most consistent with a benign osseous lesion. A transoral approach was used to excise the mass. Histologic examination demonstrated an ossifying lipoma. Postoperative imaging confirmed complete excision. The postoperative course was unremarkable, and the patient has had no recurrence at 6-month follow-up. CONCLUSIONS: This case demonstrates that a transoral approach to a lesion anterior to C1 to C2 in an adolescent can be safe, complete, and effective. LEVEL OF EVIDENCE: Case Report, level 5.

A comprehensive review of reported heritable noggin-associated syndromes and proposed clinical utility of one broadly inclusive diagnostic term: NOG-related-symphalangism spectrum disorder (NOG-SSD).

The NOG gene encodes noggin, a secreted polypeptide that is important for regulating multiple signaling pathways during human development, particularly in cartilage and bone. The hallmark of NOG-related syndromes is proximal symphalangism, defined by abnormal fusion of the proximal interphalangeal joints of the hands and feet. Many additional features secondary to NOG mutations are commonly but inconsistently observed, including a characteristic facies with a hemicylindrical nose, congenital conductive hearing loss due to stapes fixation, and hyperopia. The variable clinical presentations led to the designation of five different autosomal dominant syndromes, all subsequently found to have resulted from NOG mutations. These include (1) proximal symphalangism; (2) multiple synostoses syndrome 1; (3) stapes ankylosis with broad thumbs and toes; (4) tarsal-carpal coalition syndrome; and (5) brachydactyly type B2. Herein, we review the phenotypic features associated with mutations in the NOG gene, demonstrating the overlapping characteristics of these syndromes. Due to the variable phenotypic spectrum within families and among families with the same mutation, we propose a unifying term, NOG-related symphalangism spectrum disorder (NOG-SSD), to aid in the clinical recognition and evaluation of all affected individuals with these phenotypes. These NOG gene variants are available in a new locus-specific database (https://NOG.lovd.nl).

Identification of p.A684V missense mutation in the WFS1 gene as a frequent cause of autosomal dominant optic atrophy and hearing impairment.

Optic atrophy (OA) and sensorineural hearing loss (SNHL) are key abnormalities in several syndromes, including the recessively inherited Wolfram syndrome, caused by mutations in WFS1. In contrast, the association of autosomal dominant OA and SNHL without other phenotypic abnormalities is rare, and almost exclusively attributed to mutations in the Optic Atrophy-1 gene (OPA1), most commonly the p.R445H mutation. We present eight probands and their families from the US, Sweden, and UK with OA and SNHL, whom we analyzed for mutations in OPA1 and WFS1. Among these families, we found three heterozygous missense mutations in WFS1 segregating with OA and SNHL: p.A684V (six families), and two novel mutations, p.G780S and p.D797Y, all involving evolutionarily conserved amino acids and absent from 298 control chromosomes. Importantly, none of these families harbored the OPA1 p.R445H mutation. No mitochondrial DNA deletions were detected in muscle from one p.A684V patient analyzed. Finally, wolframin p.A684V mutant ectopically expressed in HEK cells showed reduced protein levels compared to wild-type wolframin, strongly indicating that the mutation is disease-causing. Our data support OA and SNHL as a phenotype caused by dominant mutations in WFS1 in these additional eight families. Importantly, our data provide the first evidence that a single, recurrent mutation in WFS1, p.A684V, may be a common cause of ADOA and SNHL, similar to the role played by the p.R445H mutation in OPA1. Our findings suggest that patients who are heterozygous for WFS1 missense mutations should be carefully clinically examined for OA and other manifestations of Wolfram syndrome.

A complex 6p25 rearrangement in a child with multiple epiphyseal dysplasia.

Genomic rearrangements are increasingly recognized as important contributors to human disease. Here we report on an 11½-year-old child with myopia, Duane retraction syndrome, bilateral mixed hearing loss, skeletal anomalies including multiple epiphyseal dysplasia, and global developmental delay, and a complex 6p25 genomic rearrangement. We have employed oligonucleotide-based comparative genomic hybridization arrays (aCGH) of different resolutions (44 and 244K) as well as a 1 M single nucleotide polymorphism (SNP) array to analyze this complex rearrangement. Our analyses reveal a complex rearrangement involving a ∼2.21 Mb interstitial deletion, a ∼240 kb terminal deletion, and a 70-80 kb region in between these two deletions that shows maintenance of genomic copy number. The interstitial deletion contains eight known genes, including three Forkhead box containing (FOX) transcription factors (FOXQ1, FOXF2, and FOXC1). The region maintaining genomic copy number partly overlaps the dual specificity protein phosphatase 22 (DUSP22) gene. Array analyses suggest a homozygous loss of genomic material at the 5' end of DUSP22, which was corroborated using TaqMan® copy number analysis. It is possible that this homozygous genomic loss may render both copies of DUSP22 or its products non-functional. Our analysis suggests a rearrangement mechanism distinct from a previously reported replication-based error-prone mechanism without template switching for a specific 6p25 rearrangement with a 1.22 Mb interstitial deletion. Our study demonstrates the utility and limitations of using oligonucleotide-based aCGH and SNP array technologies of increasing resolutions in order to identify complex DNA rearrangements and gene disruptions.

Autosomal dominant progressive sensorineural hearing loss due to a novel mutation in the KCNQ4 gene.

OBJECTIVE: To identify the genetic etiology in a family with autosomal dominant progressive sensorineural hearing loss. DESIGN: Prospective molecular genetic research study. SETTING: Academic genetic research laboratory. PARTICIPANTS: Seventeen members of a family with dominant progressive nonsyndromic sensorineural hearing loss: 9 affected, 6 unaffected, and 2 spouses. INTERVENTIONS: Clinical data from questionnaires, interviews, serial audiograms, and medical records; genetic data from genome-wide linkage analysis and candidate gene mutation analysis. MAIN OUTCOME MEASURES: Symptoms, age at onset, serial audiometric data, and the presence or absence of a deafness-associated mutation. RESULTS: Affected individuals in this family presented with autosomal dominant nonsyndromic high-frequency progressive sensorineural hearing loss, with age at onset ranging from 1 to 21 years. Genome-wide linkage analysis of single-nucleotide polymorphisms yielded evidence of linkage to an 18.9-Mb region on chromosome 1p34-p36, with a multipoint logarithm of odds score of 3.6. This interval contains a known deafness gene, KCNQ4, which underlies DNFA2 deafness. Sequencing of the 14 coding exons and intron-exon junctions of KCNQ4 revealed a novel heterozygous missense mutation, c.859G>C, p.Gly287Arg. The mutation disrupts the highly conserved GYG motif (glycine-tyrosine-glycine) of the phosphate-binding loop, hypothesized to be critical in maintaining pore structure and function. All 274 controls were negative for the mutation. CONCLUSIONS: Autosomal dominant high-frequency hearing loss is genetically heterogeneous, and linkage analysis is an efficient means of identifying the etiology in larger families. Deafness in this family is caused by a novel mutation in KCNQ4.

Congenital cataracts in two siblings with Wolfram syndrome.

BACKGROUND: Wolfram syndrome is characterized by optic atrophy, insulin dependent diabetes mellitus, diabetes insipidus and deafness. There are several other associated conditions reported in the literature, but congenital or early childhood cataracts are not among them. MATERIALS AND METHODS: Observational case series with confirmatory genetic analysis. RESULTS: A pair of siblings, followed over 17 years, who manifest congenital or early childhood cataracts, diabetes insipidus, diabetes mellitus, optic atrophy, and deafness. They are both compound heterozygotes for mutations (V415 deletion and A684V substitution) in the WFS1 gene. Their father has congenital sensorineural hearing loss and developed optic atrophy. He is heterozygous for A684V in WFS1. CONCLUSIONS: Wolfram syndrome should be in the differential diagnosis of genetic syndromes associated with congenital and early childhood cataracts. Here, we report on a mother who is a phenotypically normal carrier of an autosomal recessive Wolfram syndrome gene, and a father who has some of the findings of the syndrome and carries a single mutation that appears to be responsible for his hearing loss and optic atrophy. Their 2 children are compound heterozygotes and manifest the full Wolfram syndrome, in addition to cataracts.

Development of canal cholesteatoma in a patient with prenatal isotretinoin exposure.

PURPOSE: To describe the clinical and radiologic findings in a case of isotretinoin embryopathy-like syndrome and discuss management of hearing loss, congenital external auditory canal (EAC) stenosis, and EAC cholesteatoma. METHODS: Review of medical, audiological, and radiological records. RESULTS: An 8 year old female presented with bilateral moderate conductive hearing loss, bilateral microtia, left EAC stenosis, and right EAC atresia, secondary to prenatal isotretinoin exposure. Comorbidities included developmental delay, ventricular septal defect, hypotonia, and retinal maldevelopment. The left EAC was sharply upsloping with a 2mm-diameter meatus. Computed tomography (CT) scan of the temporal bone demonstrated normal middle and inner ears bilaterally; serial CT scans over 6 years demonstrated progressive development of left canal cholesteatoma. Implantation of a right BAHA system was performed, followed by left canalplasty and excision of cholesteatoma with facial nerve monitoring. An endaural incision was utilized to avoid compromising future microtia repair. Postoperative left-sided hearing improved to mild low-frequency conductive hearing loss rising to normal at 2000 Hz and above. CONCLUSIONS: Despite extensive precautions for its use, isotretinoin remains a cause of major birth defects, including sensorineural, conductive or mixed hearing loss. Congenital EAC stenosis is much less common than congenital atresia or acquired stenosis; optimal surgical approaches vary depending on hearing status and facial nerve anatomy. Close monitoring for development of canal cholesteatoma is necessary.

Increased activity of Diaphanous homolog 3 (DIAPH3)/diaphanous causes hearing defects in humans with auditory neuropathy and in Drosophila.

Auditory neuropathy is a rare form of deafness characterized by an absent or abnormal auditory brainstem response with preservation of outer hair cell function. We have identified Diaphanous homolog 3 (DIAPH3) as the gene responsible for autosomal dominant nonsyndromic auditory neuropathy (AUNA1), which we previously mapped to chromosome 13q21-q24. Genotyping of additional family members narrowed the interval to an 11-Mb, 3.28-cM gene-poor region containing only four genes, including DIAPH3. DNA sequencing of DIAPH3 revealed a c.-172G>A, g. 48G>A mutation in a highly conserved region of the 5' UTR. The c.-172G>A mutation occurs within a GC box sequence element and was not found in 379 controls. Using genome-wide expression arrays and quantitative RT-PCR, we demonstrate a 2- to 3-fold overexpression of DIAPH3 mRNA in lymphoblastoid cell lines from affected individuals. Likewise, a significant increase (approximately 1.5-fold) in DIAPH3 protein was found by quantitative immunoblotting of lysates from lymphoblastoid cell lines derived from affected individuals in comparison with controls. In addition, the c.-172G>A mutation is sufficient to drive overexpression of a luciferase reporter. Finally, the expression of a constitutively active form of diaphanous protein in the auditory organ of Drosophila melanogaster recapitulates the phenotype of impaired response to sound. To date, only two genes, the otoferlin gene OTOF and the pejvakin gene PJVK, are known to underlie nonsyndromic auditory neuropathy. Genetic testing for DIAPH3 may be useful for individuals with recessive as well as dominant inheritance of nonsyndromic auditory neuropathy.