As more and more of our genome becomes decoded, I think we’ll begin to see a proliferation of genes identified to unique behaviors that we have had no explanation for. Don’t believe me? Well, I have news that the gene most closely linked to left-handedness has been found.
The discovery has been published in Molecular Psychiatry, under the title, “LRRTM1 on chromosome 2p12 is a maternally suppressed gene that is associated paternally with handedness and schizophrenia.”
Paraphrased from National Geographic News:
“For right-handed people… the right side of the brain usually controls emotion, while the left side of the brain tends to control speech and language.
In left-handers—about 10 percent of the world’s population—the pattern is usually reversed.
“[And] this gene affects the symmetry of the brain,” Clyde Francks said. “LRRTM1 is not essential for left-handedness, but it can be a strong contributing factor.”"
The LRRTM1 gene was kinda inadvertently discovered during a study of a hundred families which intended on linking handedness with dyslexic children. LRRTM1 has other impacts on neurological functions, such as possible link to schizophrenia. Here’s more on the process and the impact it has to anthropology and human evolution,
“When the researchers took genetic samples from all the families involved, they noticed that a particular chromosome showed a correlation with handedness.”We then started to study the chromosome in detail and found this gene,” said Francks.
The team now intends to study the gene to try and tease out its full purpose and function.
“We need to find out what role it plays in brain development and at what point it is active, whether it is during fetal development, childhood, or adulthood,” Francks said.
Paul Corry, director of public affairs at Rethink, a U.K.-based mental health charity, says, “LRRTM1 “may turn out to be part of a complex relationship between a range of genes and environmental factors that lead to people developing schizophrenia.”
The gene could also help scientists understand more about how humans evolved.
Most animals have brains that are more symmetric, experts note, including our closest genetic relatives, the apes.“