title: A multivariate analysis of neuroanatomic relationships in a genetically informative pediatric sample.
abstract: An important component of brain mapping is an understanding of the relationships between neuroanatomic structures, as well as the nature of shared causal factors. Prior twin studies have demonstrated that much of individual differences in human anatomy are caused by genetic differences, but information is limited on whether different structures share common genetic factors. We performed a multivariate statistical genetic analysis on volumetric MRI measures (cerebrum, cerebellum, lateral ventricles, corpus callosum, thalamus, and basal ganglia) from a pediatric sample of 326 twins and 158 singletons. Our results suggest that the great majority of variability in cerebrum, cerebellum, thalamus and basal ganglia is determined by a single genetic factor. Though most (75%) of the variability in corpus callosum was explained by additive genetic effects these were largely independent of other structures. We also observed relatively small but significant environmental effects common to multiple neuroanatomic regions, particularly between thalamus, basal ganglia, and lateral ventricles. These findings are concordant with prior volumetric twin studies and support radial models of brain evolution.
authors.affiliation: Virginia Institute for Psychiatric and Behavioral Genetics and Departments of Psychiatry and Human Genetics, Virginia Commonwealth University, Richmond, VA 23298, USA.
authors.forename: J Eric
authors.initials: JE
authors.lastname: Schmitt
authors.forename: Gregory L
authors.initials: GL
authors.lastname: Wallace
authors.forename: Michael A
authors.initials: MA
authors.lastname: Rosenthal
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Molloy
authors.forename: Sarah
authors.initials: S
authors.lastname: Ordaz
authors.forename: Rhoshel
authors.initials: R
authors.lastname: Lenroot
authors.forename: Liv S
authors.initials: LS
authors.lastname: Clasen
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Blumenthal
authors.forename: Kenneth S
authors.initials: KS
authors.lastname: Kendler
authors.forename: Michael C
authors.initials: MC
authors.lastname: Neale
authors.forename: Jay N
authors.initials: JN
authors.lastname: Giedd
mesh_terms: D000293:Adolescent; D000465:Algorithms; D002648:Child; D002675:Child, Preschool; D030541:Databases, Genetic; D017352:Echo-Planar Imaging; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D015999:Multivariate Analysis; D009420:Nervous System / Q000033:anatomy & histology*; D010641:Phenotype; D018433:Twin Studies as Topic