Delivering a functional gene to the ears of mice with a genetic hearing disorder allows them to detect sound.
People with Usher syndrome type I have genetic mutations that cause deafness in childhood, progressive blindness and balance disorders. Gwenaëlle Géléoc at Boston Children's Hospital in Massachusetts and her colleagues studied newborn mice with a form of Usher syndrome type I. They injected a synthetic virus that carried a healthy version of the gene for a protein called harmonin into the animals' ears. The protein resides in sound-sensitive 'hair' cells of the inner ear and helps to transmit auditory signals to the brain. The team found that mice given the gene responded to sounds as quiet as whispers, similarly to normal mice. The treated mice also performed as well in balance tests as normal mice.
In another study, Luk Vandenberghe at the Schepens Eye Research Institute of Massachusetts Eye and Ear in Boston and his colleagues found that the same virus delivered genes to a large number of the target hair cells in the mouse ear.