Clinical Phenotypic Characteristics of SC26A4

Study Overview
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Brief Summary
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The presence or absence of SC26A4, whether combined with Mondini malformation, and patient age, are important factors affecting the degree of hearing loss in the Chinese population.

Detailed Description
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To summarize the Solute Carrier Family 26 Member 4 (SLC26A4) mutation and clinical phenotypic characteristics of Pendred Syndrome/Nonsyndromic Enlarged Vestibular Aqueduct (PS/NSEVA) patients and provide evidence supporting the clinical diagnosis and genetic counseling of patients with PS/NSEVA. A retrospective cohort study for the Chinese population is needed.

Official Title
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Clinical Phenotypic Characteristics of the Solute Carrier Family 26 Member 4 (SC26A4) Mutation in Pendred Syndrome/Nonsyndromic Enlarged Vestibular Aqueduct (PS/NSEVA)

Conditions
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Hearing Loss, Pendred Syndrome

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with Enlarged Vestibular Aqueduct; Patients with hearing loss; Patients with results of SLC26A4 sequencing; Exclusion Criteria: Subjects will be excluded from this study if any of the following are present: Audiometric data is incomplete Incomplete basic information Patients who did not undergo HRCT
Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Patients with enlarged vestibular aqueduct<br>This study will analyze the SLC26A4 mutation, and audiological and imaging characteristics of PS/NSEVA to summarize the clinical manifestations of PS/NSEVA patients. The study also will analyze the effects of SLC26A4 mutation and inner ear imaging on the degree of hearing loss in PS/NSEVA patients to provide predictive measures for the genetic diagnosis and clinical phenotype of PS/NSEVA. Finally, the effects of sex and age on the degree of hearing loss in patients with PS/NSEVA will be analyzed to provide insight on PS/NSEVA pathogenesis. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| SLC26A4 sequencing | Extraction from patient clinical information database and secondary use. From each patient included in the study, 3 ml of peripheral blood was collected and the DNA extracted for the diagonosis in the past. | through study completion, an average of 0.5 year | 
| High-resolution computed tomography of the temporal bone | Extraction from patient clinical information database and secondary use. High-resolution computed tomography of the temporal bone is used to measure the width of the vestibular aqueduct (VA) in the left and right ears to determine whether other inner ear malformations exist. | through study completion, an average of 0.5 year | 
| Hearing test | Extraction from patient clinical information database and secondary use. The Auditory Steady State Response test is conducted to evaluate the degree of hearing loss. | through study completion, an average of 0.5 year |