Researchers from the University of Oxford identified four DNA regions that related to handiness after they analyzed genomes of approximately 400,000 UK individuals It was found that three of those regions influenced genes that code for the proteins that have to do with brain development. The proteins have a big part in making microtubules which help with the construction of cells and form part of the cytoskeleton. The genes that help form the cytoskeleton are also what causes right and left differences in the development of animals. For example; whether a snail's shell coils to the left or to the right.
The researchers also studied brain scans of approximately 9,000 individuals from the study. They also found that with people who were left-handed, the parts of the brain that work with language worked together more orderly. This begs the question: Could people who are left-handed be better at carrying out verbal tasks? When the researchers combined the results from the brain imaging and the genetic results, they found that some of the genes related to handiness connected to cytoskeletal differences that join the language areas of the brain together. Because of these scans, for the first time, researchers were able to actually see the handedness differences in the brain.
They also found that the genes related to left-handedness had a very small increased risk of schizophrenia and a reduced risk of Parkinson's disease. Of course, this would need to be researchers further but these findings could lead to many other questions for genetic studies with these diseases. It is interesting that now we can actually see the differences of right-handed people and left-handed people in the brain scans and with studying genes as well. I think it would be good to look into these genes and how they are related to diseases more because with further research we may be able to tell who is more or less likely going to develop certain diseases, like Parkinson's or schizophrenia.