Hearing loss is a major health problem. It is the second most common cause of disability in the world. The World Health Organisation estimated in 2012 there were 360 million people worldwide with disabling hearing loss. In children this can lead to delayed language development and decreased mental well-being. In adults hearing loss has been associated with depression, isolation and decline in cognitive skills (brain functioning). Currently only hearing aids or cochlear implants can help overcome hearing loss, but these do not fix the underlying problem of permanent damage to cochlear hair cells.
Recent research has focused upon the potential of stem cells to address hearing impairment. A lot of this work has centred on two genes called Atoh1 and Six1. Alterations in these have been shown to cause deafness. Extensive work by members of our team has shown that changing the Six1 gene in mice can help to grow new hair cells. In this study we plan to show that we can do the same in human stem cells.