Name Metten Somers
Department of Psychiatry
Section Genetic basis of developmental disorders
Function PhD student, MD
E-mail:
m.somers@umcutrecht.nl Tel +31 88-7556370
Supervisor R.S. Kahn
Title research A genetic study of left-handedness and language lateralization in extended pedigrees from a Dutch population isolate.
Summary research A genetic study of left-handedness and language lateralization in extended pedigrees from a Dutch population isolate.
Background and objective Left-handedness and decreased cerebral lateralization are related, as shown by 30% of left-handers displaying left-or bilateral cerebral lateralization. Both traits are heritable and possibly share the same genetic background underpinnings. A monogenetic model has been proposed for both traits, although an oligo- or even polygenetic model can not be ruled out. This study aims to elucidate the mode of transmission as well as the genetic underpinnings of left-handedness and decreased language lateralization by performing a genetic study in over 30 extended multigenerational pedigrees with multiple left-handers from Urk, an isolated population in The Netherlands.
Study design Subjects will be identified through a validated handedness questionnaire in the local newspaper. Left-handed subjects with familial left-handedness will be contacted. We aim to include over 30 large families with three or more left-handed subjects. Participation exists of three steps: 1) measurement of language lateralization with functional Transcranial Doppler. This device measures lateralization as a function of change in flow velocity in the right and left medial cerebral arteries. During a paced letter fluency task language areas of the dominant hemisphere will be activated to a higher degree than the contralateral areas, inducing an asymmetrical increase in bloodflow in the middle cerebral arteries. 2) a small blood sample (20ml) will be obtained for DNA extraction and genetic analysis. Hereafter (co)segregation of handedness and language lateralization will be determined, as well as a genome-wide linkage.