This is what cause hearing loss in adults

Representational image

New Delhi: A new study conducted by researchers has helped to find the reason behind hearing loss in adults.

Scientists says that genetic change can cause jaw malformation which triggers hearing defects in adulthood.

Researchers from the University Of Southern California - Health Sciences explained that the structures supporting the jaws of ancestral fish gave rise to three tiny bones in the mammalian middle ear: the malleus, incus and the stapes, which transmit sound vibrations.

Therefore, if a genetic change causes a jaw malformation in a fish, an equivalent genetic change could trigger hearing defects in mice and humans.

The researchers studied two genes - JAG1 and NOTCH2 - that are mutated in most patients with Alagille Syndrome (AGS).

In nearly half of patients, AGS involves hearing loss - in addition to liver, eye, heart and skeletal defects.

While some of this is sensorineural hearing loss resulting from deficits in the sensory cells of the inner ear.

The researchers also wondered about the contribution of what is known as conductive hearing loss, involving structural components of the middle ear such as the vibrating bones.

Knowing that the equivalent genetic mutations caused jaw malformations in zebrafish, the researchers introduced the mutations into mice and observed defects in both the incus and stapes bones, and corresponding hearing loss.

(With ANI inputs)