What research is being conducted?

The National Institute on Deafness and Other Communication Disorders (NIDCD) in the United States has been working to understand hearing loss caused by inherited syndromes such as Pendred syndrome as well as from other causes. Researchers also are looking carefully at the characteristics of the disorder and how the syndrome might cause problems in such different parts of the body as the thyroid and inner ear.

Scientists continue to study the genetic basis of Pendred syndrome. The protein that the SLC26A4 gene encodes, called pendrin, is found in the inner ear, kidney, and thyroid gland. Researchers have identified more than 90 deafness-causing mutations or alterations of this gene.

Scientists have altered the gene in mice so that the mice have an abnormal SLC26A4 gene. The study of these mice is providing information on how the abnormal gene affects the form and function of different parts of the body. For example, by studying the inner ears of mice with SLC26A4 mutations, scientists now realize that the enlarged vestibular aqueduct associated with Pendred syndrome is not caused by a sudden stop in the normal development of the ear. Studies such as this are important because they help scientists rule out some causes of a disorder while helping to identify areas needing more research. Eventually, researchers are hopeful that these studies will lead to therapies that can target the basic causes of the condition.