Genetic Studies of Non-Syndromic Deafness

    Researchers at the Medical College of Virginia (MCV) and Gallaudet University have been awarded grant funding by the National Institutes of Health to attempt to identify genes that can cause hearing loss. The Gallaudet-MCV team has been studying causes of hereditary deafness for over 30 years, beginning with a nationwide study in 1969, which showed that hereditary factors (genes) are responsible for more than 50% of deafness that occurs in children. In the most common form of hereditary deafness, the deaf child may be the only deaf person in the family or may have one or more deaf siblings (recessive inheritance). In recent years the Gallaudet-MCV team has been involved in genetic studies of hearing loss that occurs in adulthood.

    More than 400 types of hereditary deafness have been identified in deaf an hard of hearing people. However, very little is known about the genes that cause these types of deafness. It is hoped that this research the will help identify the genes for some of the more common types of hereditary hearing loss.

    In 1997, one specific gene was identified which now appears to be the cause of hearing loss in many people. It is known as the CONNEXIN 26 gene. The connexins are proteins which are responsible for forming physical connections between cells. The CONNEXIN 26 gene is known to function in the inner ear. By testing for this gene, it is possible to identify the cause of deafness in as many as 20-40% of individuals in whom the cause for the deafness was previously unknown or uncertain. Testing for the CONNEXIN 26 gene is being offered as part of the study. The Gallaudet-MCV team has provided genetic evaluations and counseling services to members of the Deaf community and other deaf and hard of hearing people over the past 17 years. This experience allows the Gallaudet-MCV team to bring a unique perspective to research involving the often sensitive social and ethical issues surrounding testing for genes for deafness.

    The researchers are now recruiting deaf and hard of hearing individuals and families who are interested in participating in this project. People who have other deaf relatives as well as those who are the only deaf or hard of hearing person in their family are welcome. For more information, please contact any of the individuals below.