Evidence that it might be possible to use gene transplants to treat a common cause of deafness was published yesterday by American scientists.
The team has found that the transplant of a specific gene permits the growth of new hair cells in the inner ear – the sensory cells that pick up sound vibrations and that are lost as a result of ageing, disease, certain drugs, and the cacophony of modern life.
The technique, which one day could help millions of people worldwide, was described yesterday by Dr Yehoash Raphael of the Kresge Hearing Research Institute, University of Michigan, in the journal Nature Medicine.
Named for the hair-like projections on their surfaces, hair cells form a ribbon of vibration sensors along the length of the cochlea, the organ of the inner ear that detects sound. Receiving vibrations through the eardrum and bones of the middle ear, hair cells convert them to electrical signals carried to the brain.
Normally, humans are born with about 50,000 hair cells but since they do not regenerate, the steady loss that can accompany ageing produces significant hearing deterioration in about a third of the population by the age of 70.