Genetics of human handedness: microtubules and beyond

HighlightsHuman handedness is a moderately heritable trait.Large-scale genome-wide association and exome sequencing studies have identified multiple genes associated with handedness and highlighted a role of tubulin genes.Axon guidance, axon growth, and forming the inner structure of motile cilia are key processes regulated by tubulin genes that may also be relevant for handedness,Tubulin genes are associated with several psychiatric disorders which may offer insights into biological pathways mediating the link between handedness, brain asymmetries, and psychiatric disorders.AbstractHandedness (i.e., the preference to use either the left or the right hand for fine motor tasks) is a widely investigated trait. Handedness heritability is consistently estimated to be 25%. After decades of research, recent large-scale genome-wide association and exome sequencing studies have identified multiple genes associated with handedness and highlighted tubulin genes. Tubulin genes play a role in several processes during brain development that may be relevant for handedness ontogenesis, including axon guidance, axon growth, and forming the inner structure of motile cilia. Moreover, tubulin genes are associated with several psychiatric disorders. This finding therefore may offer insights into biological pathways mediating the link between handedness, brain asymmetries, and psychiatric traits.