Genetic Analysis of Hereditary Disorders of Hearing and Balance

May 21, 2026 updated by: National Institute on Deafness and Other Communication Disorders (NIDCD)

This study will try to identify the genetic causes of hereditary hearing loss or balance disorders.

People with a hearing or balance disorder that affects more than one family member may be eligible for this study. They and their immediate family members may undergo some or all of the following procedures:

  • Medical and family history, including questions about hearing, balance and other ear-related issues, and review of medical records.
  • Routine physical examination.
  • Blood draw or buccal swab (brushing inside the cheek to collect cells) - Tissue is collected for DNA analysis to look for changes in genes that may be related to hearing loss.
  • Hearing tests - The subject listens for tones emitted through a small earphone.
  • Balance tests to see if balance functions of the inner ear are associated with the hearing loss In one test the subject wears goggles and watches moving lights while cold or warm air is blown into the ears. A second test involves sitting in a spinning chair in a quiet, dark room.
  • Photograph - A photograph may be taken as a record of eye shape and color, distance between the eyes, and hair color.
  • Computed tomography (CT) and magnetic resonance imaging (MRI) scans - These tests show the structure of the inner ear. For CT, the subject lies still for a short time while X-ray images are obtained. For MRI, the patient lies on a stretcher that is moved into a cylindrical machine with a strong magnetic field. The magnetic field and radio waves produce images of the inner ear. The radio waves cause loud thumping noises that can be muffled by the use of earplugs.

Study Overview

Status

Completed

Conditions

Detailed Description

Hereditary hearing impairment is a genetically heterogeneous disorder that can be caused by mutations in any one of hundreds of different genes. Approximately 120 genes have now been identified in which mutations can cause nonsyndromic sensorineural hearing loss. The identification and analysis of these genes and their mutations are providing critical insights into the development, structure, and function of the auditory system, as well as the molecular mechanisms associated with disruption of these processes. In contrast, the molecular mechanisms underlying familial disorders affecting peripheral vestibular function appear to be more rare, have not been well described, and are less well understood. The peripheral auditory and vestibular systems share many common features in both health and disease, and many hereditary hearing loss disorders also affect vestibular function. The purpose of this study is to identify genes and mutations causing hereditary disorders of hearing, balance, or both. Members of families segregating hereditary disorders of hearing or balance will be enrolled in the proposed study in order to: (1) define and characterize the phenotypes and natural histories; (2) identify the underlying causative mutations and genes by linkage, positional cloning, and/or candidate gene mutation analyses; (3) and correlate observed phenotypes with the corresponding mutations and functions of the underlying genes.

Study Type

Observational

Enrollment (Actual)

335

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Nigeria
      • Ibadan, Nigeria
        • Institute of Child Health, College of Medicine, University of Ibadan
  • United States
    • Maryland
      • Bethesda, Maryland, United States, 20892
        • National Institutes of Health Clinical Center

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

No older than 99 years (Child, Adult, Older Adult)

Accepts Healthy Volunteers

No

Sampling Method

Probability Sample

Study Population

We will be studying up to 750 people with hearing losses or balance problems that are thought to be hereditary and, if possible, their family members, either with or without hearing or balance problems to participate in our study. A total of up to 400 affected and unaffected individuals, including family members and control subjects will be enrolled from the Nigerian population.

Description

  • INCLUSION CRITERIA:

Persons with known SNHL and/or peripheral vestibular dysfunctions caused by genetic etiology

Family members of persons with known SNHL and/or peripheral vestibular dysfunction caused by genetic etiology

Adults must be able to provide informed consent

Minors must have a parent or guardian able to provide informed consent

Subjects must be 0-99 years of age

For Nigeria subjects with non-syndromic hearing loss, their hearing loss must be early-onset, before 10 years of age, to be eligible.

EXCLUSION CRITERIA:

Persons with SNHL and/or peripheral vestibular dysfunction caused by a nongenetic etiology such as trauma, infection, metabolic or immunologic disorders, or exposure to ototoxic agents such as noise or aminoglycoside antibiotics will not be included in this protocol.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: Family-Based
  • Time Perspectives: Prospective

Cohorts and Interventions

Group / Cohort
1
patients with known SNHL and/or peripheral vestibular dysfunction

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
To define and characterize the phenotypes and natural histories of families with segregating hereditary disorders of balance or hearing and to identify the possible mutations and genes by genetic analysis
Time Frame: Ongoing
Characterize the natural history of hereditary disorders affecting hearing and/or balance Identify the genes, including both known and as yet undiscovered genes, that can cause hereditary disorders of hearing or balance Identify and characterize the structure and functions of these genes in the development and function of the peripheral auditory and vestibular systems Determine how mutations in these genes cause hearing loss and vestibular dysfunction Correlate genotypes and phenotypes to identify clinical features that may be used to facilitate the genetic diagnosis of hereditary disorders affecting hearing or balance
Ongoing

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

National Institute on Deafness and Other Communication Disorders (NIDCD)

Investigators

  • Principal Investigator: Thomas B Friedman, Ph.D., National Institute on Deafness and Other Communication Disorders (NIDCD)

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

December 23, 2002

Study Registration Dates

First Submitted

August 21, 2001

First Submitted That Met QC Criteria

August 21, 2001

First Posted (Estimated)

August 22, 2001

Study Record Updates

Last Update Posted (Actual)

May 22, 2026

Last Update Submitted That Met QC Criteria

May 21, 2026

Last Verified

February 23, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 010229
  • 01-DC-0229

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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