Sound and touch may seem completely separate, except possibly when playing the game Operation. But it turns out that the two senses are actually quite entwined: a new study finds that people with hearing issues often also have problems with touch.

Researchers compared sets of twins, some identical and some fraternal. The identical twins, obviously, have the same genome and thus the same mutations. The fraternal twins have genetic differences. Other subjects in the study were congenitally deaf.

To determine how acute their hearing was, the subjects reported whether they could hear various high frequencies. To evaluate touch they were asked to differentiate different surfaces with their fingertips.

The research revealed that touch sensitivity was highly heritable and connected closely with hearing ability. The better the twins could sense touch, the better they could hear, and vice versa. One in five subjects that had congenital deafness also had a poor sense of touch. The research is in the journal Public Library of Science Biology. [Henning Frenzel et al., "A Genetic Basis for Mechanosensory Traits in Humans"]

Next the researchers want to figure out which genes are faulty. After all, addressing the problem could kill two birds with one stone.

—Rose Eveleth