Gene that causes 1,000 babies to be born deaf in UK each year discovered
08:05 GMT, 1 October 2012
A gene that causes 1,000 babies to be born deaf in Britain each year has been discovered by scientists.
It is hoped the breakthrough will lead to new treatments for profound deafness.
Research published online in Nature Genetics shows babies born deaf have mutated versions of a protein called CIB2.
Two deaf children use sign language: Scientists hope their latest genetic discovery will help with developing new treatments
The gene binds to calcium within a cell and is behind a condition known as Usher syndrome type 1 that causes deafness and 'non-syndromic' hearing loss, the study shows.
Dr Zubair Ahmed, of the University of Cincinnati, said: 'In this study, researchers were able to pinpoint the gene which caused deafness in Usher syndrome type 1 as well as deafness that is not associated with the syndrome through the genetic analysis of 57 humans from Pakistan and Turkey.'
He said these findings could help researchers develop new therapeutic targets for those at risk for this syndrome.
Usher syndrome is a genetic defect that causes deafness, night-blindness and a loss of peripheral vision through the progressive degeneration of the retina.
Dr Ahmed said: 'To date, mutations affecting CIB2 are the most common and prevalent genetic cause of non-syndromic hearing loss in Pakistan. However, we have also found another mutation of the protein that contributes to deafness in Turkish populations.'
Co-researcher Dr Saima Riazuddin said: 'In animal models, CIB2 is found in the mechanosensory stereocilia of the inner ear-hair cells, which respond to fluid motion and allow hearing and balance, and in retinal photoreceptor cells, which convert light into electrical signals in the eye, making it possible to see.'
Added Dr Ahmed: 'With this knowledge, we are one step closer to understanding the mechanism of mechano-electrical transduction and possibly finding a genetic target to prevent non syndromic deafness as well as that associated with Usher syndrome type 1.'
Usher syndrome is genetic and is characterised by hearing loss, visual problems and problems with balance. In type 1, the child is profoundly deaf from birth. Hearing aids are usually of little help and sign language is used for communication.
There are also severe problems with balance, so a child may be slow to sit unsupported and is often late learning to walk.
Between three and six per cent of all children with hearing difficulties have Usher syndrome. It affects about one in every 25,000 babies born in developed countries.