Rockefeller University is looking for families with a history of hearing impairment to participate in a study aimed at identifying the genetic causes of non-syndromic hearing loss (NSHL), which is hallmarked by hearing impairment without other simultaneously occurring medical conditions. This study is part of the research program of the University's Starr Center for Human Genetics.
"By focusing on families with a history of hearing loss, we are attempting to find genes that are involved in the process of hearing. This information could aid in the development of intervention strategies to treat and prevent hearing loss," says Suzanne Leal, Ph.D., principal investigator of the study and assistant professor in the Laboratory of Statistical Genetics at Rockefeller.
Hearing impairment, which ranges in severity from modest difficulty with speech comprehension through profound hearing loss, affects 28 million Americans. About two in every 1,000 children are severely hearing impaired before adulthood. More than 60 percent of the cases of profound early-onset deafness are caused by genetic factors, which in most cases are due to single gene mutations.
According to three U.S. studies conducted between 1991 and 1993, NSHL affects three out of four individuals with genetically determined deafness. Inheritance of NSHL can be in either of two forms: autosomal dominant, in which only one copy of the hearing loss gene is necessary, or autosomal recessive, in which two copies of the gene is needed. The latter of the two forms represents approximately 75 percent of all genetic hearing loss cases.
It has been estimated that as many as 100 genes may contribute to NSHL. The locations, or loci, for more than 30 genes have been found, but scientists have identified only seven genes thus far.
Therefore, the main goals of Leal's study are to localize novel NSHL gene(s), establish the prevalence and geographical distribution of these loci, refine the genetic region for known NSHL loci, and isolate NSHL genes.
Since its inception in February 1997, the study has grown to encompass 73 families from the U.S., representing about 1,000 individuals. Families from Europe and the Middle East are also participating in the study.
Families with a history of hearing loss with at least two family members who have developed hearing loss before age 45 are being recruited for the study. Participants are asked for a copy of their hearing test results, medical records relevant to hearing loss and a small blood sample. If suitable medical records are not available for a study participant, arrangements will be made for the appropriate medical evaluations. There is no cost to study participants. All information is kept confidential.
Participants do not need to come to the university to participate in the study. The study's researchers will make arrangements to receive patient's medical records and blood samples at The Rockefeller University Hospital, the oldest hospital in the United States devoted solely to experimental medicine. Established in 1910, the hospital links laboratory investigations with bedside observations to provide a scientific basis for disease detection, prevention and treatment. This special hospital environment served as a model for the Warren G. Magnuson Clinical Center, opened at the National Institutes of Health in 1953, and similar facilities supported by federal funding at more than 75 medical schools in the United States.
Additional information on the study and NSHL is given on the study's web site http://linkage.rockefeller.edu/nshl. For further information contact Leal at (212) 327-7992.
Rockefeller University began in 1901 as the Rockefeller Institute for Medical Research, the first U.S. biomedical research center. Rockefeller faculty members have made significant achievements, including the discovery that DNA is the carrier of genetic information and the launching of the scientific field of modern cell biology. The university has ties to 19 Nobel laureates, including the president, Torsten N. Wiesel, M.D., who received the prize in 1981. In addition to the Starr Center for Human Genetics, the university recently created centers to foster research of Alzheimer's Disease, of biochemistry and structural biology, of sensory neurosciences, of immunology and immune disease, and of the links between physics and biology.