A new study of more than 1.7 million people has found a combination of factors that help understand why most people are right-handed, some are left-handed, and some are ambidextrous. A new study of more than 1.7 million people has found a combination of factors that help understand why most people are right-handed, some are left-handed, and some are ambidextrous. “Although there is an enduring fascination with whether some people are left-handed or right-handed, or both, understanding why they are is also an important research question, because being left-handed can influence brain structure and shape. in which the different functions are located within it, “explained geneticist Sarah Medlan from the Berghofer Institute of Medical Research at QIMR in Australia. According to the researchers, this is the largest study of its kind to date. This Xiaomi smart bracelet is available in Asia and some Spanish stores, such as Amazon. It comes with better autonomy and more precision in the sensors. Thus, the team has found 41 changes in the DNA base pair that are related to the possibility of a person being left-handed, while another 7 are related to the condition of being ambidextrous, according to Science Alert. Read more: They create a new superzyme capable of breaking down plastic bottles 6 times faster However, the researchers have revealed that these changes in the base pair only conferred about 12% of the variation in the “hand”, which means that there is something else that makes up the bulk of the preference for the left or right hand. “The results of our analyzes have suggested that genetic factors could only explain a small amount of variation in the condition of the hand, while environmental factors probably played a much larger role,” commented one of the researchers, Dr. University of Queensland geneticist David Evans. “This percentage was similar for ambidexterity, meaning that factors such as hand injuries or training while playing a sport or playing musical instruments are likely to play a role in a person’s ability to use both hands equally. good, “he added. In genome association studies, scientists investigate a large number of genomes and analyze which small changes in DNA are linked to a particular trait, such as the left-hander. In this regard, the researchers have collected data from the UK Biobank, 23andMe, and the International Hand Consortium to create a mega database of genome variants. Specifically, they have collected 1,766,671 data from individuals. “This large number of participants provides the statistical power to detect the effect of genes that have even very small effects on the condition of the hand,” said 23andMe statistical geneticist Gabriel Cuellar-Partida. Read more: 8 sequelae that asymptomatic COVID-19 patients could suffer, experts warn “This also highlights that large studies are needed to understand the genetic factors that influence other neurological traits and conditions and why it is so important participation in research studies, “he added. In Spain, the latest statistics indicate that there are around 12% left-handed people, a preference that begins to manifest itself even before birth, as the fetus makes smaller movements of one arm over the other. Also, differences in the hemispheres of the brain, epigenetic factors, and exposure to prenatal hormones can contribute to left-handedness. For its part, the study found that some of the genetic differences were in the microtubule genes and in the morphology of the brain. “With regard to manual dexterity, microtubule proteins play an important role during neuron development and migration, plasticity, and neurodegenerative processes,” the researchers have written. “The association between laterality and the variation of microtubule genes also allows us to understand the differences in the prevalence of various neuropsychiatric disorders and the laterality observed in some epidemiological studies,” they added. This article was published in Business Insider Spain by Geraldine Soengas.