Scientists for the first time have been able to identify the specific gene regions which have an influence on being left-handed. They have also found connections to differences in the structure of the brain in those having these variations.
It has been established before that being left or right-handed has an approximate dependence of 25 percent on the genetic code at birth. However, until now, researchers have not been able to locate the specific areas of the genome that are responsible.
The latest study involved nearly 400,000 individual records in a national database of the United Kingdom. Four genetic regions were found that were associated with handedness out of which three were linked to the proteins in the development and structure of the brain. These proteins are related to the cytoskeleton which is responsible for the construction and functionality of the cells. The study appears in the Brain Journal.
Brain scans were performed on 10,000 participants through which researchers were able to link the variations in the genetic code with white matter tracts between the language-processing regions. The cytoskeleton of the brain is present in the white matter tracts. Akira Wiberg, physician said that the large datasets from the UK Biobank helped in a deep understanding of the processes responsible for left-handedness. The language areas in the left and right sides of the brain coordinate with each other in a coordinated manner for participants with left-handedness. This might translate to left-handers having better language and verbal skills.
Human beings have an imbalance between the left-handed and right-handed individuals which is a ratio of 1:9. Cytoskeletal differences like a coil of a snail’s shell can be highly influenced by genetics. Hence scientists think the indications of the development of handedness might be initiated in the mother’s womb.
We are still at an early stage of the research to say conclusively that handedness and genes are related however this research has provided significant associations between the two instances. Scientists are now starting to understand how a dominant hand is influenced by genetic coding. This also helps in preventing any misconceptions that left-handedness is a sign of being unlucky or that being a right-handed individual is somehow superior.
Dominic Furniss, a plastic surgeon researching in molecular genetics said that through this study it has been demonstrated that left-handedness is a result of the brain’s developmental biology which is also influenced by the complex genetic interplay.
Journal Reference: Brain