A gene gives humans a sixth sense for body position

Researchers at the National Institutes of Health studied two patients with progressive scoliosis and clumsy, unsteady movement, tracing their condition to mutations in a single gene, PIEZO2, which encodes a mechanical sensor on nerve cells.

Alexander Chesler's team found that both patients had lost the ability to sense limb position and movement without looking, a sense called proprioception, along with a specific loss of light discriminative touch, while still feeling pain, temperature, and itch normally. Without visual feedback, both became far more unsteady, though they could still walk, talk and write.

The cases showed that PIEZO2 is essential in humans for proprioception and discriminative touch, but not for pain or temperature, confirming a role previously shown in mice. Ardem Patapoutian's lab had identified PIEZO2 in mouse touch cells years earlier, and this human case linked that mouse-derived gene directly to a distinct, nameable human sense.

One gene gives the body its sense of itself.