Two Genes Associated with Hearing Loss
Editor: The folks at hear-it.org are reporting on a couple of
discoveries regarding genetic causes of hearing loss. Here's their report.
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August 2008
Preliminary results from studies in Belgium and Virginia offer hope for
the future for hearing impaired people. Estimates suggest that
approximately 500 million people worldwide suffer from hearing loss.
Belgian scientists have identified the TGBF1 gene as the culprit in one
of the most common forms of hearing loss in adults, otosclerosis.
Otoschlerosis is a progressive form of hearing loss associated with the
build-up of growing bone in the middle ear, blocking sound waves from
reaching the inner ear. The current treatment options include hearing aids
or surgery. The researchers are hoping that the identification of the
TGBF1 gene will lead to even better otosclerosis treatments in the future.
Many types of hearing loss are caused by deterioration of the hair cells
in the inner ear. The hair cells process and transmit sound to the brain.
Until now it has been considered impossible to regenerate hair cells in
the ear once they disappear due to aging or exposure to excessive noise.
But a new investigation found that regeneration of hair cells in the ear
and, thus, restoration of hearing may be possible.
Scientists at the University of Virginia have done research into the
KCNQ4 gene, which, when mutating, cause genetically conditioned hearing
loss. The scientists constructed a correct form of the gene and created a
gene therapy delivery system that successfully transferred the KCNQ4 into
human hair cells harvested from the inner ear.
"This proof-of-principle experiment showed that the system we developed
works, and that KCNQ4 gene therapy might be an effective strategy to cure
deafness in patients who carry mutations of that gene", stated Professor
Jeffrey Holt of the University of Virginia.
