What kind of pain?
Geneticists have revealed the secret of a family from Italy that does not feel pain
An elderly woman from Italy, her two daughters and three grandchildren do not feel pain due to a mutation in the ZFHX2 gene, which is responsible for assembling most components of pain receptors in nerve cells, according to an article published in the journal Brain (Habib et al., A novel human pain insensitivity disorder caused by a point mutation in ZFHX2).
"If members of this family break their arms or legs, they initially feel a little pain, but it quickly passes. For example, Letizia broke her shoulder while she was skiing, and did not notice it, continuing to ski throughout the rest of the day. She only found out the next day that she had a fracture," said James Cox from University College London (in a press release Gene mutation causes low sensitivity to pain - VM).
The genome of humans and most other animals with a branched nervous system contains several dozen genes responsible for interacting with the environment and generating danger signals if some of its properties threaten human health. The most effective and universal signal of this kind is the feeling of pain, which helps people to remember dangerous objects and corners of nature and avoid them in the future.
Accordingly, if one or more of these genes break down, then their owner ceases to feel some types of pain or any pain in principle. A striking example of this is the Cape naked diggers – small rodents that almost do not react to acids, fire and many other stimuli due to mutations in several genes responsible for transmitting pain signals to the brain.
Cox and his colleagues have uncovered the genetic secrets of a unique family from Italy, whose members – a 78-year-old grandmother, her 50-year-old daughters and three teenage grandchildren - can compete with diggers in this regard by deciphering and comparing their DNA.
For the first time, scientists learned about its existence in 2008, when Italian doctors told their colleagues from universities that an unusual family of "supermen" lives in one of the cities of Italy. Its members often received fractures or severe bruises and cuts in the past, and did not notice it, continuing to use their arms and legs as if they were not broken. Doctors for a long time could not understand how this situation could arise – these people did not feel the most "serious" types of pain associated with bone and muscle injuries, but they often complained of headaches and pain in the intestines, as well as unpleasant sensations during childbirth. To answer this question, scientists decoded their DNA and studied the structure of all genes associated with pain.
As it turned out, the reason for the development of such a "superpower" was a single mutation in the ZFHX2 gene, which plays the role of a kind of regulator of the sensitivity of nerve cells in response to various pain stimuli.
Interested in its role in the work of the "pain center" in the brains of humans and other animals, scientists first removed it completely from the DNA of mice, and then transplanted a "mutant" version of ZFHX2 into it. As both of these procedures showed, rodents almost completely stopped responding to heat, burns, burning substances and other painful stimuli as a result of the fact that the work of 16 other genes whose activity is controlled by ZFHX2 changed.
Revealing the mechanisms of work and the role of this gene, as Cox notes, can help scientists create drugs that could suppress its work and temporarily "turn off" pain. At the same time, the scientists offered their wards to do the opposite and help them regain this feeling, to which they refused.
Portal "Eternal youth" http://vechnayamolodost.ru