Genetic Analysis of Hereditary Disorders of Hearing and Balance - Full Text View

Sponsor:	National Institute on Deafness and Other Communication Disorders (NIDCD)
Information provided by:	National Institutes of Health Clinical Center (CC)
ClinicalTrials.gov Identifier:	NCT00023049

Purpose

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.

Condition
Sensorineural Hearing Loss Hearing Disorder Vestibular Disease

Study Type:	Observational
Official Title:	Genetic Analysis of Hereditary Disorders of Hearing and Balance

Resource links provided by NLM:

Genetics Home Reference related topics: nonsyndromic deafness

MedlinePlus related topics: Hearing Disorders and Deafness Hearing Problems in Children

U.S. FDA Resources

Further study details as provided by National Institutes of Health Clinical Center (CC):

Estimated Enrollment:	750
Study Start Date:	August 2001
Estimated Primary Completion Date:	June 2011 (Final data collection date for primary outcome measure)

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 20 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.

Eligibility

Genders Eligible for Study:	Both
Accepts Healthy Volunteers:	No

Criteria

INCLUSION 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 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.

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.

EXCLUSION CRITERIA

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.

Contacts and Locations

Please refer to this study by its ClinicalTrials.gov identifier: NCT00023049

Contacts

Contact: Patient Recruitment and Public Liaison Office	(800) 411-1222	prpl@mail.cc.nih.gov
Contact: TTY	1-866-411-1010

Locations

United States, Maryland
National Institutes of Health Clinical Center, 9000 Rockville Pike	Recruiting
Bethesda, Maryland, United States, 20892

Sponsors and Collaborators

National Institute on Deafness and Other Communication Disorders (NIDCD)

More Information

Additional Information:

NIH Clinical Center Detailed Web Page This link exits the ClinicalTrials.gov site

Publications:

Cohn ES, Kelley PM, Fowler TW, Gorga MP, Lefkowitz DM, Kuehn HJ, Schaefer GB, Gobar LS, Hahn FJ, Harris DJ, Kimberling WJ. Clinical studies of families with hearing loss attributable to mutations in the connexin 26 gene (GJB2/DFNB1) Pediatrics. 1999 Mar;103(3):546-50.

Griffith AJ, Friedman TB. Making sense out of sound. Nat Genet. 1999 Apr;21(4):347-9. No abstract available.

Morton NE. Genetic epidemiology of hearing impairment. Ann N Y Acad Sci. 1991;630:16-31. Review. No abstract available.

Study ID Numbers:	010229, 01-DC-0229
Study First Received:	August 21, 2001
Last Updated:	August 24, 2009
ClinicalTrials.gov Identifier:	NCT00023049 History of Changes
Health Authority:	United States: Federal Government

Keywords provided by National Institutes of Health Clinical Center (CC):

Deafness
Genes
Impairment
Auditory
Vestibular

Hereditary Hearing Disorder
Hearing Impairment
Sensorineural Hearing Loss
Vestibular Dysfunction
SNHL

Additional relevant MeSH terms:

Sensation Disorders
Disease
Otorhinolaryngologic Diseases
Nervous System Diseases
Hearing Loss, Sensorineural
Vestibular Diseases
Ear Diseases

Signs and Symptoms
Deafness
Hearing Disorders
Pathologic Processes
Neurologic Manifestations
Hearing Loss
Labyrinth Diseases

ClinicalTrials.gov processed this record on November 30, 2009