Researchers have uncovered more than 40 genes associated with being left handed, Psychology Today reports.
An international team of researchers conducted a large genome-wide association study of handedness. As they describe in a preprint posted to BioRxiv, they used data from the UK Biobank, 23andMe and 32 studies from the International Handedness Consortium — a total 1.5 million right-handed, 194,198 left-handed, and 37,637 ambidextrous individuals — to find 41 genes linked to being left handed and seven genes linked to being ambidextrous.
Eight of these left-handed linked loci were also near genes involved in microtubule formation and regulation, and the researchers, who were led by QIMR Berghofer Medical Research Institute's Sarah Medland, note that microtubule proteins are important for various key brain development processes and have been implicated in neuropsychiatric conditions. Additionally, they uncovered a link between left-handedness and the 17q21.31 locus, a region where a deletion has been tied to the intellectual disability and developmental delay syndrome Koolen de Vries.
"The study clearly shows that left-handedness is polygenic," Psychology Today notes. "The functional roles of the genes connected to left-handedness clearly show that it originates in the brain, not the hands itself."