NIH Clinical Research Studies

Protocol Number: 97-DC-0180

Active Accrual, Protocols Recruiting New Patients

Genetic Analysis of Human Hereditary Hearing Impairment
This studied is designed to discover the genes that cause hearing impairment. More precisely, this study aims to map and clone genes that are important for the development and maintenance of the anatomy and physiology related to hearing (auditory system).

The study will begin by finding large families who have members with hearing impairment. Once families are found, members with and without hearing impairment will be evaluated by an audiologist and a clinician (doctor). An audiologist, is a person trained in evaluating, habilitating, and rehabilitating people with disorders of hearing function. The clinician's responsibility is to examine the patients and check for other signs and symptoms related to hearing.

Finding the gene for hearing impairment requires:

1. DNA samples of hearing impaired family members, taken from standard blood samples.

2. DNA samples of members of the family without hearing impairment, taken from standard blood samples.

3. Results of hearing tests conducted by the audiologist for all participants.

Once all members of the family are evaluated researchers can create a pedigree. A pedigree is like a family tree that charts members of a family with a genetic disorder, like hearing impairment. Pedigrees are used to determine the mode of inheritance of the gene responsible for a particular condition.

Finally, researcher intend on using all the information gathered as well as methods for genetic analysis to map out the location of the gene. Patients participating in this study will not directly benefit from its research, but scientific understanding achieved may help researchers better understand the auditory system and someday prevent deafness.

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:

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).

We seek subjects who are members of large families with multiple individuals affected with a hearing disorder. Sporadic cases will occasionally 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.

If there is evidence of genetic homogeneity, small families can be pooled for linkage analysis, or a combination of large and small families can be pooled.

Subjects of any ethnic background, gender, age, sexual orientation, or health status will be included.


Patients will be excluded when their hearing or vestibular dysfunction are 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
Linkage Analysis
Positional Cloning
Mutation Screening
Recruitment Keyword(s):
Syndromic Hearing Impairment
Non-Syndromic Hearing Impairment
Partial Hearing Loss
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


Citation(s): Not Provided

Active Accrual, Protocols Recruiting New Patients

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