Scientists find deafness gene through mutant mice

Scientists in Hong Kong and Britain have discovered a gene responsible for hearing, a breakthrough that could eventually lead to a cure for congenital deafness.

The scientists worked for 12 years on the project, eventually tracing deafness in mutant yellow mice back to a defective gene, said the project’s lead scientist, Kathryn Cheah from the University of Hong Kong.

The master gene, called Sox2, is responsible for the development of hair cells and supporting cells in the inner ear that enable hearing, the Hong Kong scientists and teams at Britain’s Medical Research Council and University of Nottingham found.

Any mutation or disruption in the gene leads to hearing loss and balance problems in mice, they found.

Ears of mice are very similar to those in humans and such findings in the rodent may be applicable to humans, who suffer loss of hearing when hair cells in their inner ears die, Cheah said.

“If you want to develop therapies to regulate hair cells in the ears of people who are deaf, then you really need to have a gene that is a master gene,” Cheah said in an interview.

“The implication is that perhaps we can now explore ways of using Sox2 to help develop new ways of regenerating hair cells in humans. This is in the long term.”

The discovery of the role of Sox2 began with the creation in 1993 of a mutant yellow mouse by a biochemistry PhD student in Cheah’s department.

The mouse, dubbed Yellow Submarine, displayed abnormal behavior such as running in circles. It could not swim, had problems balancing and was partially deaf.

Deafness is more common than is often known. One in every 800 children is born with a hearing impairment and 60 percent of people over the age of 70 suffer some hearing loss.

Scientists in Britain had produced a similar mutant mouse but totally deaf, helping the Hong Kong team trace Yellow Submarine’s deafness to an errant Sox2 master gene on chromosome 3.

Provided by ArmMed Media
Revision date: June 22, 2011
Last revised: by Tatiana Kuznetsova, D.M.D.