Posted April 3, 2018
Hearing loss can cause people to change their lives dramatically. People may withdraw from contact with others because they no longer can enjoy favorite activities, participate in conversations or remember dates and conversations. Hearing loss can occur for many reasons, such as exposure to loud noises or a severe accident. But it also can be caused by a medical or hereditary condition, such as Usher syndrome type 3.
Three things to know about Usher syndrome type 3 hereditary hearing loss:
- It’s rare – About 2 percent of the population is affected by Usher syndrome type 3. It is most common in people from Finland and some descendants of Jewish ancestry.
- Progresses with age – People diagnosed with Usher Syndrome type 3 have normal hearing at birth. However, during the teenage years, they start experiencing hearing loss. As adults, they may need hearing aids, and by middle age, they can be completely deaf. Some people also experience vision loss.Years ago, scientists discovered that Usher syndrome type 3 is caused by a defect in the Clarin-1 gene. This gene assists in making the CLRN1 protein in hair cells. The inner ear contains thousands of hair cells that act as mini speakers to transmit sounds entering the ear to the brain where it’s interpreted. If these hairs are damaged, hearing loss can result.
- New research offers hope – Historically, there has been no known cure for Usher syndrome type 3. However, researchers at Case Western Reserve University School of Medicine found, through studies of mice, that gene therapy could be effective in curtailing hearing loss caused by this syndrome. In tests, scientists transplanted normal protein cells into those that were malfunctioning or missing in the inner ear. They found that gene therapy could block progressive hearing loss and improve hearing in the affected mice.
- This research represents at least two firsts in science:
- Experts successfully mimicked in an animal the progressive hearing loss found in patients with Usher syndrome type 3 hearing loss.
- It is the first study to show that by using Clarin-1 gene therapy, hearing loss can be restricted in mice with Usher syndrome type 3.
Scientists are conducting new studies with gene therapy to define further how to restrict the development of Usher syndrome type 3 to prevent hearing loss and deafness in humans.