Morphology Studies of the Human Fetal Cochlea in Turner Syndrome

Behavioral Assessment of Central Auditory Processing in Turner Syndrome

Introduction  Turner syndrome (TS) affects ∼ 1 in 2,500 live births. The presence of hearing alterations is one of the comorbidities found in this syndrome. Objective  The present study aimed to evaluate the central auditory abilities in TS and to associate the alterations found with the cytogenetic pattern of the syndrome. Methods  We included children and adults aged 9 to 39 years old, diagnosed with TS, with numerical or structural alterations of sex chromosomes in their karyotype. A battery of behavioral tests of central auditory processing (CAP) was performed, including a test within the modalities: monoaural low-redundancy, dichotic listening, binaural interaction, and temporal processing (resolution and ordering). We studied auditory skills in the total sample and in the sample stratified by age, divided into groups: G1 (9 to 13 years old), G2 (14 to 19 years old), and G3 (20 to 31 years old). For the association of the cytogenetic pattern, the division was T1 (chromosome monosomy X), and T2 (other TS cytogenetic patterns). Statistical analysis presented data expressed as median and interquartile range for numerical data and as frequency and percentage for categorical data. Results  We found alterations in four auditory skills in the three age groups, but there was a statistically significant difference between the age groups only in the Gaps in Noise Test (GIN) ( p -value = 0.009). Regarding karyotype, a greater number of alterations in the T1 cytogenetic pattern (chromosome monosomy X) was observed in four auditory skills, but without a statistically significant difference. Conclusion  The alterations found point to an impairment in CAP in TS.

Association between cytogenetic alteration and the audiometric profile of individuals with Turner syndrome

INTRODUCTION

Turner syndrome is a frequent genetic disorder that affects female individuals and covers a large phenotypic variability. Scientific literature suggests an association between hearing loss and Turner syndrome, but it remains a controversial topic.

OBJECTIVE

To associate the cytogenetic alteration with the audiometric profile of individuals with Turner syndrome.

METHODS

Cross-sectional study, with a hospital-based, convenience sample. Patients diagnosed with Turner syndrome were included and those with difficulty understanding the audiometry and/or other associated syndromes were excluded. The participants were studied with pure tone audiometry.

RESULTS

Of the 65 patients included, 36.9% had X chromosome monosomy and 63.0% had other alterations. Regarding the audiometry, 64.6% had normal thresholds and 35.3% had hearing impairment. Of these, 30.4% had hybrid hearing loss, 26.0% alteration at 6 and/or 8kHz, 17.3% had conductive hearing loss, 13.0% sensorineural loss and 13.0% had mixed hearing loss. We observed that the mild degree was the most frequent one. There was no statistically significant association between the cytogenetic type of Turner syndrome and the presence or absence of hearing loss, or with the type and degree of hearing loss.

CONCLUSION

The cytogenetic alteration in Turner syndrome was not associated with the audiometric profile, which showed variability regarding the type and degree of hearing loss.

"Donating our bodies to science": A discussion about autopsy and organ donation in Turner syndrome

At the Third Turner Resource Network Symposium, a working group presented the results of collaborative discussions about the importance of autopsy in Turner syndrome (TS). Considerable gaps in understanding the causes of death in TS can only be closed by more frequent death investigations and autopsies. The presentation included an overview of autopsy methods, strategies for utilizing autopsy, and biobanking to address research questions about TS, and the role of palliative care in the context of autopsy. This review highlights strategies to promote autopsy and tissue donation, culminating with an action plan to increase autopsy rates in the TS community.

Hearing loss among patients with Turner's syndrome: literature review1

Introduction

Turner's syndrome (TS) is caused by a partial or total deletion of an X chromosome, occurring in 1:2,000 to 1:5,000 live born females. Hearing loss is one of its major clinical manifestations. However, there are few studies investigating this problem.

Objectives

To review the current knowledge regarding the epidemiology, etiology, clinical manifestations and diagnosis of hearing impairment in patients with TS.

Methods

A bibliographic search was performed in the Medline and Lilacs databanks (1980-2012) to identify the main papers associating Turner's syndrome, hearing impairment and its clinical outcomes.

Conclusions

Recurrent otitis media, dysfunction of the Eustachian tube, conductive hearing loss during infancy and sensorineural hearing loss in adolescence are the audiologic disorders more common in ST. The karyotype appears to be important in the hearing loss, with studies demonstrating an increased prevalence in patients with monosomy 45,X or isochromosome 46,i(Xq). Morphologic studies of the cochlea are necessary to help out in the clarifying the etiology of the sensorineural hearing loss.

Manifestações clínicas e fonoaudiológicas na Síndrome de Turner: estudo bibliográfico

TEMA: síndrome genética e achados fonoaudiológicos. OBJETIVO: descrever as manifestações clínicas e fonoaudiológicas em indivíduos com a Síndrome de Turner CONCLUSÃO: foram levantados 23 artigos sobre a Síndrome de Turner dos quais 7 discorriam sobre a audição e suas alterações nesses indivíduos, 6 sobre linguagem receptiva e/ou expressiva e praxia, 5 sobre aspectos psicológicos e cognitivos além de 28 artigos referentes às manifestações clínicas em geral. Por meio do levantamento bibliográfico pode-se observar que as manifestações fonoaudiológicas na Síndrome de Turner são pouco estudadas e, dentro da fonoaudiologia as manifestações audiológicas como perda de audição e otites são as mais estudadas, ao contrário dos aspectos práxicos e de recepção/ expressão da linguagem.

Mondini deformity in a case of Turner syndrome. A radiological finding

Turner syndrome (TS) is the human being's most frequent sex chromosome abnormality. Progressive sensorineural hearing loss is documented in more than 50% of the women affected by this syndrome. Although Mondini defect is the cochlear congenital malformation most frequently identified in other polymalformative syndromes, it has rarely been reported in TS. We describe the case of a 32-year-old woman with TS who presented progressive sensorineural hearing loss. The computed tomography of the ears showed bilateral Mondini deformity.

Growth hormone treatment does not affect incidences of middle ear disease or hearing loss in infants and toddlers with Turner syndrome

CONTEXT

No randomized, controlled, prospective study has evaluated the effect of growth hormone (GH) on the rates of middle ear (ME) disease and hearing loss in girls with Turner syndrome (TS).

DESIGN

A 2-year, prospective, randomized, controlled, open-label, multicenter, clinical trial ('Toddler Turner Study'; August 1999 to August 2003) was carried out.

SETTING

The study was conducted at 11 US pediatric endocrine centers.

SUBJECTS

Eighty-eight girls with TS, aged 9 months to 4 years, were enrolled.

INTERVENTION

The interventions comprised recombinant GH (50 microg/kg/day, n = 45) or no treatment (n = 43) for 2 years.

MAIN OUTCOME MEASURES

The outcome measures included occurrence rates of ear-related problems, otitis media (OM) and associated antibiotic treatments, tympanometric assessment of ME function and hearing assessment by audiology.

RESULTS

At baseline, 57% of the girls (mean age = 1.98 +/- 1.00 years) had a history of recurrent OM, 33% had undergone tympanostomy tube (t-tube) insertion and 27% had abnormal hearing. There was no significant difference between the treatment groups for annual incidence of OM episodes (untreated control: 1.9 +/- 1.4; GH-treated: 1.5 +/- 1.6, p = 0.17). A quarter of the subjects underwent ear surgeries (mainly t-tube insertions) during the study. Recurrent or persistent abnormality of ME function on tympanometry was present in 28-45% of the girls without t-tubes at the 6 postbaseline visits. Hearing deficits were found in 19-32% of the girls at the annual postbaseline visits. Most of these were conductive deficits, however, 2 girls had findings consistent with sensorineural hearing loss, which was evident before 3 years of age.

CONCLUSIONS

Ear and hearing problems are common in infants and toddlers with TS and are not significantly influenced by GH treatment. Girls with TS need early, regular and thorough ME monitoring by their primary care provider and/or otolaryngologist, and at least annual hearing evaluations by a pediatric audiologist.

Histology and synchrotron radiation-based microtomography of the inner ear in a molecularly confirmed case of CHARGE syndrome

CHARGE (Coloboma of the iris or retina, heart defects, atresia of the choanae, retardation of growth and/or development, genital anomalies, ear anomalies) syndrome (OMIM #214800) affects about 1 in 10,000 children and is most often caused by chromodomain helicase DNA-binding protein-7 (CHD7) mutations. Inner ear defects and vestibular abnormalities are particularly common. Specifically, semicircular canal (SCC) hypoplasia/aplasia and the presence of a Mondini malformation can be considered pathognomonic in the context of congenital malformations of the CHARGE syndrome. We obtained a temporal bone (TB) of a patient with CHARGE syndrome who died from bacteremia at 3 months of age. The clinical diagnosis was confirmed in the patient by direct DNA sequencing and the detection of a de novo, truncating CHD7 mutation, c.6169dup (p.R2057fs). We assessed changes of the TB and the degree of neural preservation, which may influence the potential benefit of cochlear implantation. The TB was analyzed using synchrotron radiation-based micro computed tomography, and by light microscopy. The vestibular partition consisted of a rudimentary vestibule with agenesis of the SCCs. The cochlea was hypoplastic with poor or deficient interscaling and shortened (Mondini dysplasia). The organ of Corti had near normal structure and innervation. Modiolus and Rosenthal's canal were hypoplastic with perikarya displaced along the axon bundles into the internal acoustic meatus, which may be explained by the arrest or limited migration and translocation of the cell nuclei into the cochlear tube during development.

Epidermal growth factor receptor expression in human fetal cochlea with Turner syndrome

HYPOTHESIS

Growth hormones have beneficial effects on increasing height in adults with Turner syndrome (TS) and may also affect auditory function.

BACKGROUND

Turner syndrome is the most common sex-linked chromosomal abnormality in female conceptions. Epidermal growth factor and its receptor (EGFR) affect differentiation, proliferation, and migration of epithelial cells and function as survival factors. The expression of EGFR is found in the developing and juvenile inner ear of experimental animals but is absent in adults.

METHODS

To determine whether EGFR plays a role in TS, its expression was analyzed in the cochlea of healthy fetus and fetus with TS and in healthy adults.

RESULTS

In healthy fetuses, EGFR protein expression was localized to the inner and outer hair cells and the Reissner membrane. The fetuses with TS on the 13th gestational week (GW) showed a similar pattern of immunoreactivity as the normal 16th and 20th GW cochlea. By the 23rd GW, EGFR immunoreactivity was not detectable in the TS hair cells or the Reissner membrane, and less intensive staining was found in the surrounding fibrocytes of the spiral ganglion.

CONCLUSION

This is the first demonstration of EGFR immunoreactivity in the human cochlea and illustrates how EGFR expression is altered during development in TS. These findings indicate the importance of growth hormone receptors for inner ear development in humans.