Language lateralization is a key feature of human brain organization, but the molecular mechanisms underlying its ontogenesis are still poorly understood. In the present study a team of scientist from the Department of Human Genetics and the Institute of Cognitive Neuroscience investigated whether variation in schizophrenia-related genes modulates individual lateralization patterns. For the first time, a significant association of genetic variation in the cholecystokinin-A receptor (CCKAR) and language lateralization was found. Individuals carrying the schizophrenia risk allele C of this polymorphism showed a marked reduction of the typical left-hemispheric dominance for language processing. Since the cholecystokinin A receptor is involved in dopamine release in the central nervous system, these findings suggest that genetic variation in this receptor may modulate language lateralization due to its impact on dopaminergic pathways.

Ocklenburg, S., Arning, L., Gerding, W.M., Epplen, J.T., Güntürkün, O. et al. (2013). Cholecystokinin A Receptor (CCKAR) Gene Variation Is Associated with Language Lateralization. PLoS ONE 8(1): e53643.