title: Quantitative tract-based white matter heritability in twin neonates.
abstract: Studies in adults indicate that white matter microstructure, assessed with diffusion tensor imaging (DTI), has high heritability. Little is known about genetic and environmental influences on DTI parameters, measured along fiber tracts particularly, in early childhood. In the present study, we report comprehensive heritability data of white matter microstructure fractional anisotropy (FA), radial diffusion (RD), and axial diffusion (AD) along 47 fiber tracts using the quantitative tractography in a large sample of neonatal twins (n=356). We found significant genetic influences in almost all tracts with similar heritabilities for FA, RD, and AD as well as positive relationships between these parameters and heritability. In a single tract analysis, genetic influences along the length of the tract were highly variable. These findings suggest that at birth, there is marked heterogeneity of genetic influences of white matter microstructure within white matter tracts. This study provides a basis for future studies of developmental changes in genetic and environmental influences during early childhood, a period of rapid development that likely plays a major role in individual differences in white matter structure and function.
authors.affiliation: Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Department of Psychiatry, Kyungpook National University School of Medicine, Daegu 700721, South Korea.
authors.forename: Seung Jae
authors.initials: SJ
authors.lastname: Lee
authors.affiliation: Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
authors.forename: Rachel J
authors.initials: RJ
authors.lastname: Steiner
authors.affiliation: Department of Statistics, North Carolina State University, Raleigh, NC 27695, USA.
authors.forename: Shikai
authors.initials: S
authors.lastname: Luo
authors.affiliation: Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, VA 23298, USA.
authors.forename: Michael C
authors.initials: MC
authors.lastname: Neale
authors.affiliation: Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Department of Computer Science, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
authors.forename: Martin
authors.initials: M
authors.lastname: Styner
authors.affiliation: Department of Biostatics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
authors.forename: Hongtu
authors.initials: H
authors.lastname: Zhu
authors.affiliation: Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. Electronic address: jgilmore@med.unc.edu.
authors.forename: John H
authors.initials: JH
authors.lastname: Gilmore
mesh_terms: D001921:Brain / Q000033:anatomy & histology*; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D059647:Gene-Environment Interaction; D006801:Humans; D007231:Infant, Newborn; D040582:Inheritance Patterns; D008297:Male; D066127:White Matter / Q000033:anatomy & histology*
keywords: Axial diffusivity; Diffusion tensor imaging (DTI); Fractional anisotropy; Genetics; Quantitative tractography; Radial diffusivity