Anatomic, functional and cognitive asymmetries in monozygotic twins with discordant handedness

Discordant handedness was observed at a higher rate than expected in monozygotic (MZ) twins. This study was designed to investigate the degree of asymmetry in terms of anatomical, functional (motor) and cognitive (IQ and visual memory) features on 27 MZ twins for discordant handedness according to Edinburgh Handedness Inventory (EHI). There was statistically significant difference between EHI and Yetkin Laterality Questionnaire (YLQ). Ambidextrous were found lack of cerebral dominance. Both left and right handed subjects were found left hemisphere dominance. There was no significant difference in terms of anatomic or cognitive features between MZ twin members with discordant handedness.