Around 1 in 200 people in the UK will lose their hearing due to a condition called otosclerosis, which affects the smallest bone in the body, the stirrup (or stapes) bone in the middle ear. In otosclerosis, this bone becomes fixed in place due to overgrowth around the joint of the bone. This means it can no longer move to pass on sound waves to the inner ear – which causes a conductive hearing loss. People with otosclerosis typically begin to lose their hearing as young adults, in their late teens or twenties.
Currently people with otosclerosis either use hearing aids, which are not always effective, or have surgery to remove part of the stirrup bone and replace it with a prosthetic device. This improves hearing in about 80% of people, but it does not restore full normal hearing.
The main aim of Nadhrah’s project is to investigate how the stapes bone forms during development, what changes occur to make the stapes bone develop abnormally, and the biological processes that are usually active to prevent the stapes bone from becoming fixed. She will study genetically engineered mice in which the stapes bone develops abnormally to identify the key processes and molecules that are important for the development of this bone. She will then use a variety of methods to study these processes, and what happens when they are interfered with, in cell lines in the lab, to understand more about the changes that occur in the middle ear.
Nadhrah’s project will increase our understanding of how and why otosclerosis occurs. This will help researchers to develop drug treatments to prevent further overgrowth of the stapes bone or alternatively, to stimulate the removal of bone in this area. This could provide effective therapies for otosclerosis, as alternatives to current invasive surgical options or permanent reliance on hearing aids.