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Whether or not a person suffers hearing loss due to loud noise may depend on their genes, research suggests. 

Noise-induced hearing loss, caused or made worse by work, is one of the most common work-related illnesses and members of the armed forces are particularly vulnerable.

In 2013, the US Department of Veterans Affairs reported hearing loss as one of the most common ailments among veterans receiving disability compensation.

In a new genome-wide association study, an international team led by Keck Medicine of the University of Southern California (USC) neuroscientists has found evidence that some people may be more genetically susceptible to noise-induced hearing loss than others.

Noise-induced hearing loss is one of the most common work-related illnesses in the United States, according to the National Institute for Occupational Safety and Health. At especially high risk are troops in the Armed Forces. In 2013, the Department of Veterans Affairs reported hearing loss as one of the most common disabilities among veterans receiving disability compensation.

Those at higher, genetic risk for hearing loss may decide to take additional precautionary measures to protect their hearing prior to hazardous noise exposure, study authors say.

'Understanding the biological processes that affect susceptibility to hearing loss due to loud noise exposure is an important factor in reducing the risk,' said Keck Medicine of USC otologist Rick A. Friedman, M.D., Ph.D., professor of otolaryngology and neurosurgery at the Keck School of Medicine of USC and senior author of the study. 

'We have made great advances in hearing restoration, but nothing can compare to protecting the hearing you have and preventing hearing loss in the first place.'

The study, 'Genome-wide association study identifies Nox3 as a critical gene for susceptibility to noise-induced hearing loss,' appears in the April 16 edition of PLOS Genetics, a peer-reviewed scientific journal.

While some gene association studies on noise-induced hearing loss in people have been conducted in the past, all were very small and their results un-replicated. Genome-wide association studies, or GWAS, search the entire genome for common genetic variants to see if any of those variants are associated with a trait. Mouse GWAS have lead to the discovery of hundreds of genes involved in complex traits that have immediate relevance to people.

In the USC study, conducted at the Zilkha Neurogenetic Institute, Friedman's team identified the Nox3 gene, which is almost exclusively expressed in the inner ear, as a key gene for susceptibility to noise-induced hearing loss. Using 64 of the 100 strains of mice in the Hybrid Mouse Diversity Panel, the team was able to increase the statistical power of its investigation, leading to the first published GWAS for noise-induced hearing loss in mice.

More research is necessary before clinical recommendations can be made.

But a team of scientists at the University of Southern California believe they now have the concrete answer.

They have identified a gene, named Nox3, found in the inner ear, that is crucial in determining how vulnerable a person is to developing hearing loss. 

Their study, looking at the DNA of mice exposed to noise, marks the first piece of genome-wide association research.

The researchers said those people who are at greater genetic risk of suffering hearing loss, should think about taking precautionary measures to protect themselves prior to hazardous noise exposure.   

Professor Rick Friedman, of the University of Southern California, said: 'Understanding the biological processes that affect susceptibility to hearing loss due to loud noise exposure is an important factor in reducing the risk.

'We have made great advances in hearing restoration, but nothing can compare to protecting the hearing you have and preventing hearing loss in the first place.'

While some gene association studies on noise induced hearing loss in people have been conducted in the past, all were very small and their results unreplicated.

Genome wide association studies search the entire DNA for common mutations to see if any of those are linked with a trait. 

Mouse genome wide association studies have lead to the discovery of hundreds of genes involved in complex traits that have immediate relevance to people.

Beethoven, who suffered from a severe form of tinnitus, first mentioned his hearing problems at the comparatively tender age of 31.

Around 1801, he began to lose it. The composer suffered a 'roar' in his ears that made it hard for him to appreciate music and he would avoid conversation.

The cause of his deafness remains a mystery but it has variously been attributed to syphilis, lead poisoning, typhus or possibly even his habit of immersing his head in cold water to stay awake.

Now, the researchers ask in their paper published in PLOS Genetics: 'Did Beethoven or old rockers go deaf because of this gene?'