A new study conducted on the genetic data of 350,000 people has found that left-handed people are more likely to have some particular coding variants in a specific gene that codes for the production of a particular protein fundamental to the structure of the cell.
As often happens with what is perceived as “different” by the majority, even i mancini have been objects of curiosity for centuries and prejudices by right-handed people. According to the latest available data, in fact, using the left hand instead of the right is a rather rare characteristic: About 10% of the population is left-handedor about one in ten people.
On why some people are born left-handed scientists have been wondering for some time: Now we may finally be close to an answer. A group of geneticists from Max Planck Institute for Psycholinguisticsa leading psycholinguistic institute in the Netherlands, has discovered that there is one genetic variant which may be partly associated with left-handedness.
The mystery of left-handedness
During the Middle Ages for a woman, being left-handed could mean being accused of witchcraft and end up at the stake. But you don’t need to go that far back in time to find evidence of how being left-handed has been difficult for society to accept: only a few decades ago in Italy it was common practice in schools try to “correct” left-handed children to the sound of the wand and punishments.
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Part of this hostility was also a consequence of the fact that until recently no one had an answer to the question: Why are some people left-handed? In more recent times, scientists and researchers have also asked themselves this question, who, study after study, have begun to find the individual pieces of this complex puzzle.
Thus it was discovered that left-handedness occurs when theright cerebral hemisphere is more dominant of the left one, which instead prevails in right-handed people. Subsequent research revealed the role that genetics could have in determining left-handedness. One of thesecarried out in 2019 by the University of Oxford on data from 400,000 people, identified four portions of DNA potentially involved.
What the new study added
The study, published in early April 2024 on Nature Communicationsexamined the genome of 350,000 people (313,271 right-handed and 38,043 left-handed), using data from Uk Biobank, a vast database that has collected biomedical data from thousands of residents in the United Kingdom since 2006. Their goal was to try to locate what genes were involved in determining left-handedness.
By studying this huge amount of genetic data, researchers from the Dutch institute found that left-handed people had almost three times more (2.7) more likely to have some rare ones coding variants in a specific gene, identified as TUBB4B. It is a gene that codes for the production of tubulini.e. the protein at the base of microtubules, some constituent elements of the cytoskeleton, the load-bearing skeleton of the cell.
It is not yet clear – warn the researchers – how the development of microtubules, and therefore of itself cell structure, is linked to the development of left-handedness, but this suggests the existence of a connection between our inclination to use the right or left hand and the deep structure of the cells. Furthermore, given that left-handedness tends to manifest itself in higher percentages in the presence of various neurodevelopmental disordersstudying the mechanisms that give it away could provide valuable new information in this field too.