NIH Clinical Research Studies

Protocol Number: 01-DC-0229

Active Accrual, Protocols Recruiting New Patients

Genetic Analysis of Hereditary Disorders of Hearing and Balance
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.

Sponsoring Institute:
National Institute on Deafness and Other Communication Disorders (NIDCD)
Recruitment Detail
Type: Participants currently recruited/enrolled
Gender: Male & Female
Referral Letter Required: No
Population Exclusion(s): None

Eligibility Criteria:

Patients with known SNHL and/or peripheral vestibular dysfunction will be recruited.

It is anticipated that, in most cases, patients will be recruited whose disorders do not appear to be syndromic (i.e., are not associated with extra-auditory or extra-vestibular features).

Patients segregating abnormal auditory or vestibular phenotypes associated with novel syndromic phenotypes, or syndromes in which the causative gene has not been identified, will be eligible for this study.

The majority of subjects will be members of large families with multiple individuals affected with a hearing or balance disorder.

Sporadic cases will occassionally be included when the phenotype has features suggestive of mutations in one or a few particular candidate genes, since autosomal or X-Linked recessive inheritance can appear to be sporadic.

Children will be included when they are affected with the mutant phenotype or, based upon pedigree analysis, they may not be unaffected but are genetically informative and contributory for linkage mapping and identification of the mutated gene segregating in their family.


Patients will be excluded when their hearing or vestibular dysfunction is known to be caused by a nongenetic etiology such as trauma, infection, metabolic or immunologic disorders, or exposure to ototoxic agents such as noise or aminoglycoside antibiotics.

Special Instructions:
Currently Not Provided
Recruitment Keyword(s):
Hereditary Hearing Disorder
Hearing Impairment
Sensorineural Hearing Loss
Vestibular Dysfunction
Sensorineural Hearing Loss
Hearing Disorder
Vestibular Disease
Investigational Drug(s):
Investigational Device(s):
Supporting Site:
National Institute on Deafness and Other Communication Disorders

Patient Recruitment and Public Liaison Office
Building 61
10 Cloister Court
Bethesda, Maryland 20892-4754
Toll Free: 1-800-411-1222
TTY: 301-594-9774 (local),1-866-411-1010 (toll free)
Fax: 301-480-9793


Clinical studies of families with hearing loss attributable to mutations in the connexin 26 gene (GJB2/DFNB1)

Making sense out of sound

Genetic epidemiology of hearing impairment

Active Accrual, Protocols Recruiting New Patients

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