Genetic link found to noise-induced hearing loss

5 July 2006

Belgian scientists have pinpointed three genes that could explain why only some people exposed to loud noise suffer hearing loss.

The breakthrough is expected to pave the way for new treatments and means of preventing noise-induced hearing loss.

Although exposure to loud noise has long been known to cause hearing loss and is a leading occupational hazard in many countries, exactly why some people are more susceptible has been less apparent.

Now scientists have found that three genes are responsible for influencing the risk of developing noise-induced hearing loss - a condition which is irreversible. The genes discovered by Professor Guy Van Camp and researchers at the University of Antwerp are involved in the recycling of potassium in the inner ear, which is essential for normal hearing.

Van Camp found the genes while studying more than 1,000 men who had been exposed to loud noise while working in paper pulp mills and steel factories in Sweden. Nearly 80 per cent had been subjected to noise for at least 20 years.

After testing the men's hearing, the scientists did a genetic analysis of the 10 per cent who were most sensitive to noise and an equal number who were most resistant and compared the results.

"Significant differences between susceptible and resistant workers were found in the sequence of 3 genes, KCNE1, KCNQ1 and KCNQ4," said Van Camp who reported the findings in the journal Human Mutations.

"Further studies on KCNE1 show the version of the gene associated with increased risk to noise causes the encoded ion channel to open more rapidly than the normal version. This could affect the recycling of potassium making people with this version of the gene more sensitive to noise," he added.

Source: Press release
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