Pain-Suppressing Mutation Discovered
The mutation of a certain gene can suppress all pain perception in humans. Scientists led by Geoffrey Woods from the British University of Cambridge were able to identify the change in six individuals from three related families from Pakistan who had never felt pain in their lives.
It turned out that the family members carry a mutation in the SCN9A gene on chromosome 2. This genetic factor in turn encodes a protein subunit in the voltage-gated sodium channel NaV1.7, which is primarily found in pain receptors and their neurons.
Voltage-gated sodium channels embedded in the cell membrane open as soon as the electrical voltage across the membrane drops, allowing sodium ions to flow into the cell. As a result, the membrane tension drops even further, so that further channels are opened. These ion channels thus play an essential role in the conduction of nerve cells.
Animal experiments had already shown that NaV1.7 is involved in the perception of pain; however, the exact function of the subunit affected by the mutation remains unclear. The scientists hope to be able to specifically combat pain by blocking the channel - especially since the mutation carriers appear perfectly he althy apart from the lack of pain perception.
The scientists had stumbled across the rare cases of pain tolerance experienced by a Pakistani boy who monetized his skills on the street: stabbing his arms with knives and walking on hot coals. Before his 14th birthday he died as a result of jumping from a house roof. (aj)
