Touch and hearing are very distinct, but German scientists have found a possible genetic link between the two sensory systems.
Superficially, the two senses might seem worlds apart, but both rely on the ability to translate motions - vibrations in the ear and movement and pressure on the skin - into signals to the brain. A common set of molecules or mechanisms might be at work.
To determine if touch sensitivity can be inherited genetically, Henning Frenzel of the Max-Delbruck Center for Molecular Medicine and his colleagues first examined 100 pairs of fraternal and identical twins in a study outlined in the journal PLoS Biology in Tuesday.
They tested the twins on two kinds of touch sensitivity traits: "vibration detection threshold," or how low a vibration the subject could detect with their pinky finger; and "tactile acuity," or the ability to distinguish between two pressure points on the skin that are very close together.
Since the identical twins are genetically identical and the fraternal twins share up to 50 percent of the same genes, any genetic effect on touch should be more pronounced in the former.
Next, Frenzel and his team calculated the heritability of the two traits, a figure that explains the degree to which genetic variation contributed to the variation in the traits seen in the subjects. On average, 28 percent of the differences in tactile acuity and 52 percent of the differences in vibration detection could be chalked up to genetic influence.
Original citation: Frenzel, H., Bohlender, J., Pinsker, K., Wohlleben, B., Tank, J., et al. (2012). A Genetic Basis for Mechanosensory Traits in Humans, PLoS Biol 10(5): e1001318. doi:10.1371/journal.pbio.1001318
In : Auditory