Genetic Analysis of Hereditary Disorders of Hearing and Balance

Brief Title

Genetic Analysis of Hereditary Disorders of Hearing and Balance

Official Title

Genetic Analysis of Hereditary Disorders of Hearing and Balance

Brief Summary

      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.
    

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

Primary Outcome

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

Condition

Sensorineural Hearing Loss

Study Arms / Comparison Groups

 1

Description:  patients with known SNHL and/or peripheral vestibular dysfunction

Publications

* Includes publications given by the data provider as well as publications identified by National Clinical Trials Identifier (NCT ID) in Medline.

Estimated Enrollment

335

Start Date

December 23, 2002

Eligibility Criteria

        -  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.
      

Gender

All

Ages

N/A - 99 Years

Accepts Healthy Volunteers

No

Contacts

Thomas B Friedman, Ph.D., , 

Location Countries

Nigeria

Location Countries

Nigeria

NCT ID

NCT00023049

Organization ID

010229

Secondary IDs

01-DC-0229

Responsible Party

Sponsor

Study Sponsor

National Institute on Deafness and Other Communication Disorders (NIDCD)

Study Sponsor

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

Verification Date

May 10, 2022