Hearing and touch sensitivity may be genetically linked

London, May 14 (ANI): Sensitivity to touch is heritable and apparently linked to hearing as well, according to a new study.

Gary Lewin and colleagues at the Max Delbruck Center for Molecular Medicine in Berlin, Germany, gauged touch in 100 healthy pairs of fraternal and identical twins.

The researchers tested finger sensitivity in two distinct methods: by response to a high-frequency vibration and the ability to identify the orientation of very fine grating.

Lewin's team found that up to 50 per cent of the variation in sensitivity to touch was genetically determined. Audio tests also showed that those with good hearing were more likely to have sensitive touch. The link between the two is logical, as both touch and hearing rely on sensory cells that detect mechanical forces, New Scientist reported.

Then the researchers studied touch sensitivity in students suffering from congenital deafness. They found that 1 in 5 also had impaired touch, suggesting that some genes causing deafness may also dull the sense of touch. When they looked at a subset of individuals who were deaf and blind because of Usher syndrome, they found that mutations in a single gene, USH2A, caused both the disease and reduced sensitivity to touch.

The next move is to try and identify more genes that affect our sense of touch.

"There are many more genes than just the one we found," said Lewin, adding that finding them "will hopefully show us more about the biology of touch." (ANI)