PT  - JOURNAL ARTICLE
AU  - Zhiqiang Sha
AU  - Antonietta Pepe
AU  - Dick Schijven
AU  - Amaia Carrion Castillo
AU  - James M. Roe
AU  - René Westerhausen
AU  - Marc Joliot
AU  - Simon E. Fisher
AU  - Fabrice Crivello
AU  - Clyde Francks
TI  - Left-handedness and its genetic influences are associated with structural asymmetries mapped across the cerebral cortex in 31,864 individuals
AID  - 10.1101/2021.07.16.452594
DP  - 2021 Jan 01
TA  - bioRxiv
PG  - 2021.07.16.452594
4099  - http://biorxiv.org/content/early/2021/07/16/2021.07.16.452594.short
4100  - http://biorxiv.org/content/early/2021/07/16/2021.07.16.452594.full
AB  - Roughly 10% of the human population is left-handed, and this rate is increased in some brain-related disorders. The neuroanatomical correlates of hand preference have remained equivocal. We re-sampled structural brain image data from 28,802 right-handers and 3,062 left-handers (UK Biobank population dataset) to a symmetrical surface template, and mapped asymmetries for each of 8,681 vertices across the cerebral cortex in each individual. Left-handers and right-handers showed average differences of surface area asymmetry within fusiform, anterior insular, anterior-middle-cingulate and precentral cortex. Meta-analyzed functional imaging data implicated these regions in executive functions and language. Polygenic disposition to left-handedness was associated with two of these regional asymmetries, and 18 loci previously linked with left-handedness by genome-wide screening showed associations with one or more of these asymmetries. Implicated genes included six encoding microtubule-related proteins: TUBB, TUBA1B, TUBB3, TUBB4A, MAP2 and NME7 – the latter is mutated in left-right reversal of the visceral organs. There were also two cortical regions where average thickness asymmetry was altered in left-handedness: on the postcentral gyrus and inferior occipital cortex, functionally annotated with hand sensorimotor and visual roles. These cortical thickness asymmetries were not heritable. Heritable surface area asymmetries of language-related regions may link the etiologies of hand preference and language, whereas non-heritable asymmetries of sensorimotor cortex may manifest as consequences of hand preference.Competing Interest StatementThe authors have declared no competing interest.