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:
- < TAB> DNA samples of hearing impaired family members, taken from standard blood samples.
- < TAB> DNA samples of members of the family without hearing impairment, taken from standard blood samples.
- < TAB> 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.< TAB>
Partial Hearing Loss
|Official Title:||Genetic Analysis of Human Hereditary Hearing Impairment|
|Study Start Date:||September 1997|
The objective of this research project is to map and clone genes that are important for the normal development or maintenance of the auditory system. One strategy for identifying some of the genes important for auditory processes is to ascertain large families each with several hearing impaired individuals. Initial contact will be made by family physicians, audiologist, supervisors in schools for the hearing impaired, and directly by the principal investigators during surveys of schools for the deaf and visits with hearing impairment self-help groups. Members of a family will be evaluated by an audiologist, and instances of hearing impairment will be documented and categorized. A clinician would then examine hearing impaired and unaffected members of the family for the presence of other clinical features so as to distinguish between nonsyndromic and syndromic forms of hearing impairment. Pedigrees of these families will be analyzed to determine the mode of inheritance of the hereditary hearing impairment segregating in each family. Families will be ascertained through audiologists and other clinicians, genetics clinics, schools for the hearing impaired and through linguists and medical anthropologists who study unique sign languages and the sociology of communities with a high proportion of hearing impaired individuals. The mutated gene will then be genetically mapped by a linkage or association based strategy, using DNA typing of highly polymorphic genetic markers distributed across the human genome.
Please refer to this study by its ClinicalTrials.gov identifier: NCT00001606
|United States, Maryland|
|National Institutes of Health Clinical Center, 9000 Rockville Pike|
|Bethesda, Maryland, United States, 20892|
|Principal Investigator:||Thomas B Friedman, Ph.D.||National Institute on Deafness and Other Communication Disorders (NIDCD)|