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Videtta G, Colli C, Squarcina L, Fagnani C, Medda E, Brambilla P, Delvecchio G. Heritability of white matter in twins: A diffusion neuroimaging review. Phys Life Rev 2024; 50:126-136. [PMID: 39079258 DOI: 10.1016/j.plrev.2024.07.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2024] [Accepted: 07/03/2024] [Indexed: 09/02/2024]
Abstract
Diffusion neuroimaging has emerged as an essential non-invasive technique to explore in vivo microstructural characteristics of white matter (WM), whose integrity allows complex behaviors and cognitive abilities. Studying the factors contributing to inter-individual variability in WM microstructure can provide valuable insight into structural and functional differences of brain among individuals. Genetic influence on this variation has been largely investigated in twin studies employing different measures derived from diffusion neuroimaging. In this context, we performed a comprehensive literature search across PubMed, Scopus and Web of Science of original twin studies focused on the heritability of WM. Overall, our results highlighted a consistent heritability of diffusion indices (i.e., fractional anisotropy, mean, axial and radial diffusivity), and network topology among twins. The genetic influence resulted prominent in frontal and occipital regions, in the limbic system, and in commissural fibers. To enhance the understanding of genetic influence on WM microstructure further studies in less heterogeneous experimental settings, encompassing all diffusion indices, are warranted.
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Affiliation(s)
- Giovanni Videtta
- Department of Biomedical Sciences for Health, University of Milan, Milan, Italy
| | - Chiara Colli
- Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
| | - Letizia Squarcina
- Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
| | - Corrado Fagnani
- Centre for Behavioural Sciences and Mental Health, Istituto Superiore di Sanità, Rome, Italy
| | - Emanuela Medda
- Centre for Behavioural Sciences and Mental Health, Istituto Superiore di Sanità, Rome, Italy
| | - Paolo Brambilla
- Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy; Department of Neurosciences and Mental Health, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, via F. Sforza 35, Milan 20122, Italy
| | - Giuseppe Delvecchio
- Department of Neurosciences and Mental Health, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, via F. Sforza 35, Milan 20122, Italy.
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Functional cortical associations and their intraclass correlations and heritability as revealed by the fMRI Human Connectome Project. Exp Brain Res 2022; 240:1459-1469. [PMID: 35292842 DOI: 10.1007/s00221-022-06346-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 03/04/2022] [Indexed: 11/04/2022]
Abstract
We report on the functional connectivity (FC), its intraclass correlation (ICC), and heritability among 70 areas of the human cerebral cortex. FC was estimated as the Pearson correlation between averaged prewhitened Blood Oxygenation Level-Dependent time series of cortical areas in 988 young adult participants in the Human Connectome Project. Pairs of areas were assigned to three groups, namely homotopic (same area in the two hemispheres), ipsilateral (both areas in the same hemisphere), and heterotopic (nonhomotopic areas in different hemispheres). ICC for each pair of areas was computed for six genetic groups, namely monozygotic (MZ) twins, dizygotic (DZ) twins, singleton siblings of MZ twins (MZsb), singleton siblings of DZ twins (DZsb), non-twin siblings (SB), and unrelated individuals (UNR). With respect to FC, we found the following. (a) Homotopic FC was stronger than ipsilateral and heterotopic FC; (b) average FCs of left and right cortical areas were highly and positively correlated; and (c) FC varied in a systematic fashion along the anterior-posterior and inferior-superior dimensions, such that it increased from anterior to posterior and from inferior to superior. With respect to ICC, we found the following. (a) Homotopic ICC was significantly higher than ipsilateral and heterotopic ICC, but the latter two did not differ significantly from each other; (b) ICC was highest for MZ twins; (c) ICC of DZ twins was significantly lower than that of the MZ twins and higher than that of the three sibling groups (MZsb, DZsb, SB); and (d) ICC was close to zero for UNR. Finally, with respect to heritability, it was highest for homotopic areas, followed by ipsilateral, and heterotopic; however, it did not differ statistically significantly from each other.
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Pfeifer LS, Schmitz J, Papadatou-Pastou M, Peterburs J, Paracchini S, Ocklenburg S. Handedness in twins: meta-analyses. BMC Psychol 2022; 10:11. [PMID: 35033205 PMCID: PMC8760823 DOI: 10.1186/s40359-021-00695-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 11/24/2021] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND In the general population, 10.6% of people favor their left hand over the right for motor tasks. Previous research suggests higher prevalence of atypical (left-, mixed-, or non-right-) handedness in (i) twins compared to singletons, and in (ii) monozygotic compared to dizygotic twins. Moreover, (iii) studies have shown a higher rate of handedness concordance in monozygotic compared to dizygotic twins, in line with genetic factors playing a role for handedness. METHODS By means of a systematic review, we identified 59 studies from previous literature and performed three sets of random effects meta-analyses on (i) twin-to-singleton Odds Ratios (21 studies, n = 189,422 individuals) and (ii) monozygotic-to-dizygotic twin Odds Ratios (48 studies, n = 63,295 individuals), both times for prevalence of left-, mixed-, and non-right-handedness. For monozygotic and dizygotic twin pairs we compared (iii) handedness concordance Odds Ratios (44 studies, n = 36,217 twin pairs). We also tested for potential effects of moderating variables, such as sex, age, the method used to assess handedness, and the twins' zygosity. RESULTS We found (i) evidence for higher prevalence of left- (Odds Ratio = 1.40, 95% Confidence Interval = [1.26, 1.57]) and non-right- (Odds Ratio = 1.36, 95% Confidence Interval = [1.22, 1.52]), but not mixed-handedness (Odds Ratio = 1.08, 95% Confidence Interval = [0.52, 2.27]) among twins compared to singletons. We further showed a decrease in Odds Ratios in more recent studies (post-1975: Odds Ratio = 1.30, 95% Confidence Interval = [1.17, 1.45]) compared to earlier studies (pre-1975: Odds Ratio = 1.90, 95% Confidence Interval = [1.59-2.27]). While there was (ii) no difference between monozygotic and dizygotic twins regarding prevalence of left- (Odds Ratio = 0.98, 95% Confidence Interval = [0.89, 1.07]), mixed- (Odds Ratio = 0.96, 95% Confidence Interval = [0.46, 1.99]), or non-right-handedness (Odds Ratio = 1.01, 95% Confidence Interval = [0.91, 1.12]), we found that (iii) handedness concordance was elevated among monozygotic compared to dizygotic twin pairs (Odds Ratio = 1.11, 95% Confidence Interval = [1.06, 1.18]). By means of moderator analyses, we did not find evidence for effects of potentially confounding variables. CONCLUSION We provide the largest and most comprehensive meta-analysis on handedness in twins. Although a raw, unadjusted analysis found a higher prevalence of left- and non-right-, but not mixed-handedness among twins compared to singletons, left-handedness was substantially more prevalent in earlier than in more recent studies. The single large, recent study which included birth weight, Apgar score and gestational age as covariates found no twin-singleton difference in handedness rate, but these covariates could not be included in the present meta-analysis. Together, the secular shift and the influence of covariates probably make it unsafe to conclude that twinning has a genuine relationship to handedness.
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Affiliation(s)
- Lena Sophie Pfeifer
- Cognitive Psychology, Institute of Cognitive Neuroscience, Faculty of Psychology, Ruhr University Bochum, Universitätsstraße 150, 44780, Bochum, Germany.
| | - Judith Schmitz
- School of Medicine, University of St Andrews, St Andrews, Scotland
| | - Marietta Papadatou-Pastou
- School of Education, Department of Primary Education, National and Kapodistrian University of Athens, Athens, Greece
- Biomedical Research Foundation of the Academy of Athens, Athens, Greece
| | - Jutta Peterburs
- Institute of Systems Medicine and Department of Human Medicine, MSH Medical School Hamburg, Hamburg, Germany
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Matijevic S, Ryan L. Tract Specificity of Age Effects on Diffusion Tensor Imaging Measures of White Matter Health. Front Aging Neurosci 2021; 13:628865. [PMID: 33790778 PMCID: PMC8006297 DOI: 10.3389/fnagi.2021.628865] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 02/11/2021] [Indexed: 11/13/2022] Open
Abstract
Well-established literature indicates that older adults have poorer cerebral white matter integrity, as measured through diffusion tensor imaging (DTI). Age differences in DTI have been observed widely across white matter, although some tracts appear more sensitive to the effects of aging than others. Factors like APOE ε4 status and sex may contribute to individual differences in white matter integrity that also selectively impact certain tracts, and could influence DTI changes in aging. The present study explored the degree to which age, APOE ε4, and sex exerted global vs. tract specific effects on DTI metrics in cognitively healthy late middle-aged to older adults. Data from 49 older adults (ages 54–92) at two time-points separated by approximately 2.7 years were collected. DTI metrics, including fractional anisotropy (FA) and mean diffusivity (MD), were extracted from nine white matter tracts and global white matter. Results showed that across timepoints, FA and MD increased globally, with no tract-specific changes observed. Baseline age had a global influence on both measures, with increasing age associated with lower FA and higher MD. After controlling for global white matter FA, age additionally predicted FA for the genu, callosum body, inferior fronto-occipital fasciculus (IFOF), and both anterior and posterior cingulum. Females exhibited lower global FA on average compared to males. In contrast, MD was selectively elevated in the anterior cingulum and superior longitudinal fasciculus (SLF), for females compared to males. APOE ε4 status was not predictive of either measure. In summary, these results indicate that age and sex are associated with both global and tract-specific alterations to DTI metrics among a healthy older adult cohort. Older women have poorer white matter integrity compared to older men, perhaps related to menopause-induced metabolic changes. While age-related alterations to white matter integrity are global, there is substantial variation in the degree to which tracts are impacted, possibly as a consequence of tract anatomical variability. The present study highlights the importance of accounting for global sources of variation in DTI metrics when attempting to investigate individual differences (due to age, sex, or other factors) in specific white matter tracts.
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Affiliation(s)
- Stephanie Matijevic
- Cognition and Neuroimaging Laboratory, Department of Psychology, University of Arizona, Tucson, AZ, United States
| | - Lee Ryan
- Cognition and Neuroimaging Laboratory, Department of Psychology, University of Arizona, Tucson, AZ, United States
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Zhang J, Xia K, Ahn M, Jha SC, Blanchett R, Crowley JJ, Szatkiewicz JP, Zou F, Zhu H, Styner M, Gilmore JH, Knickmeyer RC. Genome-Wide Association Analysis of Neonatal White Matter Microstructure. Cereb Cortex 2021; 31:933-948. [PMID: 33009551 PMCID: PMC7786356 DOI: 10.1093/cercor/bhaa266] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 07/15/2020] [Accepted: 08/16/2020] [Indexed: 11/14/2022] Open
Abstract
A better understanding of genetic influences on early white matter development could significantly advance our understanding of neurological and psychiatric conditions characterized by altered integrity of axonal pathways. We conducted a genome-wide association study (GWAS) of diffusion tensor imaging (DTI) phenotypes in 471 neonates. We used a hierarchical functional principal regression model (HFPRM) to perform joint analysis of 44 fiber bundles. HFPRM revealed a latent measure of white matter microstructure that explained approximately 50% of variation in our tractography-based measures and accounted for a large proportion of heritable variation in each individual bundle. An intronic SNP in PSMF1 on chromosome 20 exceeded the conventional GWAS threshold of 5 x 10-8 (p = 4.61 x 10-8). Additional loci nearing genome-wide significance were located near genes with known roles in axon growth and guidance, fasciculation, and myelination.
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Affiliation(s)
- J Zhang
- Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - K Xia
- Department of Psychiatry, University of North Carolina, Chapel Hill, NC, USA
| | - M Ahn
- Department of Mathematics and Statistics, University of Nevada, Reno, NV, USA
| | - S C Jha
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - R Blanchett
- Genetics and Genome Sciences Program, Michigan State University, East Lansing, MI, USA
| | - J J Crowley
- Department of Psychiatry, University of North Carolina, Chapel Hill, NC, USA
- Department of Genetics, University of North Carolina, Chapel Hill, NC, USA
- Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden
| | - J P Szatkiewicz
- Department of Psychiatry, University of North Carolina, Chapel Hill, NC, USA
- Department of Genetics, University of North Carolina, Chapel Hill, NC, USA
| | - F Zou
- Department of Biostatistics, University of North Carolina, Chapel Hill, NC, USA
| | - H Zhu
- Department of Biostatistics, University of North Carolina, Chapel Hill, NC, USA
| | - M Styner
- Department of Psychiatry, University of North Carolina, Chapel Hill, NC, USA
| | - J H Gilmore
- Department of Psychiatry, University of North Carolina, Chapel Hill, NC, USA
| | - R C Knickmeyer
- Department of Psychiatry, University of North Carolina, Chapel Hill, NC, USA
- Department of Pediatrics and Human Development, Michigan State University, East Lansing, MI, USA
- Institute for Quantitative Health Sciences and Engineering, Michigan State University, East Lansing, MI, USA
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Jin X, Liang X, Gong G. Functional Integration Between the Two Brain Hemispheres: Evidence From the Homotopic Functional Connectivity Under Resting State. Front Neurosci 2020; 14:932. [PMID: 33122984 PMCID: PMC7566168 DOI: 10.3389/fnins.2020.00932] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Accepted: 08/11/2020] [Indexed: 12/12/2022] Open
Abstract
Functional integration among neural units is one of the fundamental principles in brain organization that could be examined using resting-state functional connectivity (rs-FC). Interhemispheric functional integration plays a critical role in human cognition. Homotopic functional connectivity (HoFC) under resting state provide an avenue to investigate functional integration between the two brain hemispheres, which can improve the present understanding of how interhemispheric interactions affect cognitive processing. In this review, we summarize the progress of HoFC studies under resting state and highlight how these findings have enhanced our understanding of interhemispheric functional organization of the human brain. Future studies are encouraged to address particular methodological issues and to further ascertain behavioral correlates, brain disease's modulation, task influence, and genetic basis of HoFC.
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Affiliation(s)
- Xinhu Jin
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, China
| | - Xinyu Liang
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, China
| | - Gaolang Gong
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, China
- Beijing Key Laboratory of Brain Imaging and Connectomics, Beijing Normal University, Beijing, China
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7
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Gustavson DE, Hatton SN, Elman JA, Panizzon MS, Franz CE, Hagler DJ, Fennema-Notestine C, Eyler LT, McEvoy LK, Neale MC, Gillespie N, Dale AM, Lyons MJ, Kremen WS. Predominantly global genetic influences on individual white matter tract microstructure. Neuroimage 2019; 184:871-880. [PMID: 30296555 PMCID: PMC6289256 DOI: 10.1016/j.neuroimage.2018.10.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 08/06/2018] [Accepted: 10/04/2018] [Indexed: 01/30/2023] Open
Abstract
Individual differences in white matter tract microstructure, measured with diffusion tensor imaging (DTI), demonstrate substantial heritability. However, it is unclear to what extent this heritability reflects global genetic influences or tract-specific genetic influences. The goal of the current study was to quantify the proportion of genetic and environmental variance in white matter tracts attributable to global versus tract-specific influences. We assessed fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) across 11 tracts and 22 subdivisions of these tracts in 392 middle-aged male twins from the Vietnam Era Twin Study of Aging (VETSA). In principal component analyses of the 11 white matter tracts, the first component, which represents the global signal, explained 50.1% and 62.5% of the variance in FA and MD, respectively. Similarly, the first principal component of the 22 tract subdivisions explained 38.4% and 47.0% of the variance in FA and MD, respectively. Twin modeling revealed that DTI measures of all tracts and subdivisions were heritable, and that genetic influences on global FA and MD accounted for approximately half of the heritability in the tracts or tract subdivisions. Similar results were observed for the AD and RD diffusion metrics. These findings underscore the importance of controlling for DTI global signals when measuring associations between specific tracts and outcomes such as cognitive ability, neurological and psychiatric disorders, and brain aging.
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Affiliation(s)
- Daniel E Gustavson
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA; Center for Behavior Genetics of Aging, University of California, San Diego, La Jolla, CA, USA.
| | - Sean N Hatton
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA; Center for Behavior Genetics of Aging, University of California, San Diego, La Jolla, CA, USA; Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
| | - Jeremy A Elman
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA; Center for Behavior Genetics of Aging, University of California, San Diego, La Jolla, CA, USA
| | - Matthew S Panizzon
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA; Center for Behavior Genetics of Aging, University of California, San Diego, La Jolla, CA, USA
| | - Carol E Franz
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA; Center for Behavior Genetics of Aging, University of California, San Diego, La Jolla, CA, USA
| | - Donald J Hagler
- Department of Radiology, University of California, San Diego, La Jolla, CA, USA
| | - Christine Fennema-Notestine
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA; Department of Radiology, University of California, San Diego, La Jolla, CA, USA
| | - Lisa T Eyler
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA; Mental Illness Research, Education, And Clinical Center, Veterans Affairs San Diego Healthcare System, La Jolla, CA, USA
| | - Linda K McEvoy
- Department of Radiology, University of California, San Diego, La Jolla, CA, USA
| | - Michael C Neale
- Virginia Institute for Psychiatric and Behavior Genetics, Virginia Commonwealth University, Richmond, VA, USA
| | - Nathan Gillespie
- Virginia Institute for Psychiatric and Behavior Genetics, Virginia Commonwealth University, Richmond, VA, USA
| | - Anders M Dale
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA; Department of Radiology, University of California, San Diego, La Jolla, CA, USA
| | - Michael J Lyons
- Department of Psychological and Brain Sciences, Boston University, Boston, MA, USA
| | - William S Kremen
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA; Center for Behavior Genetics of Aging, University of California, San Diego, La Jolla, CA, USA; Center of Excellence for Stress and Mental Health, Veterans Affairs San Diego Healthcare System, La Jolla, CA, USA
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8
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Hatton SN, Panizzon MS, Vuoksimaa E, Hagler DJ, Fennema‐Notestine C, Rinker D, Eyler LT, Franz CE, Lyons MJ, Neale MC, Tsuang MT, Dale AM, Kremen WS. Genetic relatedness of axial and radial diffusivity indices of cerebral white matter microstructure in late middle age. Hum Brain Mapp 2018; 39:2235-2245. [PMID: 29427332 PMCID: PMC5895525 DOI: 10.1002/hbm.24002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 01/24/2018] [Accepted: 02/01/2018] [Indexed: 01/30/2023] Open
Abstract
Two basic neuroimaging-based characterizations of white matter tracts are the magnitude of water diffusion along the principal tract orientation (axial diffusivity, AD) and water diffusion perpendicular to the principal orientation (radial diffusivity, RD). It is generally accepted that decreases in AD reflect disorganization, damage, or loss of axons, whereas increases in RD are indicative of disruptions to the myelin sheath. Previous reports have detailed the heritability of individual AD and RD measures, but have not examined the extent to which the same or different genetic or environmental factors influence these two phenotypes (except for corpus callosum). We implemented bivariate twin analyses to examine the shared and independent genetic influences on AD and RD. In the Vietnam Era Twin Study of Aging, 393 men (mean age = 61.8 years, SD = 2.6) underwent diffusion-weighted magnetic resonance imaging. We derived fractional anisotropy (FA), mean diffusivity (MD), AD, and RD estimates for 11 major bilateral white matter tracts and the mid-hemispheric corpus callosum, forceps major, and forceps minor. Separately, AD and RD were each highly heritable. In about three-quarters of the tracts, genetic correlations between AD and RD were >.50 (median = .67) and showed both unique and common variance. Genetic variance of FA and MD were predominately explained by RD over AD. These findings are important for informing genetic association studies of axonal coherence/damage and myelination/demyelination. Thus, genetic studies would benefit from examining the shared and unique contributions of AD and RD.
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Affiliation(s)
- Sean N. Hatton
- Department of PsychiatryUniversity of California, San DiegoLa JollaCalifornia,Center for Behavior Genetics of AgingUniversity of California, San DiegoLa JollaCalifornia
| | - Matthew S. Panizzon
- Department of PsychiatryUniversity of California, San DiegoLa JollaCalifornia,Center for Behavior Genetics of AgingUniversity of California, San DiegoLa JollaCalifornia
| | - Eero Vuoksimaa
- Institute for Molecular Medicine Finland, University of HelsinkiFinland
| | - Donald J. Hagler
- Department of RadiologyUniversity of California, San DiegoLa JollaCalifornia
| | - Christine Fennema‐Notestine
- Department of PsychiatryUniversity of California, San DiegoLa JollaCalifornia,Department of RadiologyUniversity of California, San DiegoLa JollaCalifornia
| | - Daniel Rinker
- Department of PsychiatryUniversity of California, San DiegoLa JollaCalifornia,Department of RadiologyUniversity of California, San DiegoLa JollaCalifornia,Imaging Genetics CenterInstitute for Neuroimaging and Informatics, University of Southern CaliforniaLos AngelesCalifornia
| | - Lisa T. Eyler
- Department of PsychiatryUniversity of California, San DiegoLa JollaCalifornia,Mental Illness Research Education and Clinical Center, VA San Diego Healthcare SystemSan DiegoCalifornia
| | - Carol E. Franz
- Department of PsychiatryUniversity of California, San DiegoLa JollaCalifornia,Center for Behavior Genetics of AgingUniversity of California, San DiegoLa JollaCalifornia
| | - Michael J. Lyons
- Department of Psychological and Brain SciencesBoston UniversityBostonMassachusetts
| | - Michael C. Neale
- Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University School of MedicineRichmondVirginia
| | - Ming T. Tsuang
- Department of PsychiatryUniversity of California, San DiegoLa JollaCalifornia,Center for Behavior GenomicsUniversity of California, San DiegoLa JollaCalifornia,Institute for Genomic Medicine, University of California, San DiegoLa JollaCalifornia
| | - Anders M. Dale
- Department of RadiologyUniversity of California, San DiegoLa JollaCalifornia,Department of NeurosciencesUniversity of California, San DiegoLa JollaCalifornia
| | - William S. Kremen
- Department of PsychiatryUniversity of California, San DiegoLa JollaCalifornia,Center for Behavior Genetics of AgingUniversity of California, San DiegoLa JollaCalifornia,Center of Excellence for Stress and Mental Health, VA San Diego Healthcare SystemLa JollaCalifornia
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9
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Vuoksimaa E, Panizzon MS, Hagler DJ, Hatton SN, Fennema-Notestine C, Rinker D, Eyler LT, Franz CE, Lyons MJ, Neale MC, Tsuang MT, Dale AM, Kremen WS. Heritability of white matter microstructure in late middle age: A twin study of tract-based fractional anisotropy and absolute diffusivity indices. Hum Brain Mapp 2016; 38:2026-2036. [PMID: 28032374 DOI: 10.1002/hbm.23502] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2016] [Revised: 12/08/2016] [Accepted: 12/12/2016] [Indexed: 12/14/2022] Open
Abstract
There is evidence that differences among individuals in white matter microstructure, as measured with diffusion tensor imaging (DTI), are under genetic control. However, little is known about the relative contribution of genetic and environmental effects on different diffusivity indices among late middle-aged adults. Here, we examined the magnitude of genetic influences for fractional anisotropy (FA), and mean (MD), axial (AD), and radial (RD) diffusivities in male twins aged 56-66 years old. Using an atlas-based registration approach to delineate individual white matter tracts, we investigated mean DTI-based indices within the corpus callosum, 12 bilateral tracts and all these regions of interest combined. All four diffusivity indices had high heritability at the global level (72%-80%). The magnitude of genetic effects in individual tracts varied from 0% to 82% for FA, 0% to 81% for MD, 8% to 77% for AD, and 0% to 80% for RD with most of the tracts showing significant heritability estimates. Despite the narrow age range of this community-based sample, age was correlated with all four diffusivity indices at the global level. In sum, all diffusion indices proved to have substantial heritability for most of the tracts and the heritability estimates were similar in magnitude for different diffusivity measures. Future studies could aim to discover the particular set of genes that underlie the significant heritability of white matter microstructure. Hum Brain Mapp 38:2026-2036, 2017. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Eero Vuoksimaa
- Department of Psychiatry, University of California, San Diego, La Jolla, California.,Center for Behavior Genetics of Aging University of California, San Diego, La Jolla, California.,Institute for Molecular Medicine Finland and Department of Public Health, University of Helsinki, Helsinki, Finland
| | - Matthew S Panizzon
- Department of Psychiatry, University of California, San Diego, La Jolla, California.,Center for Behavior Genetics of Aging University of California, San Diego, La Jolla, California
| | - Donald J Hagler
- Department of Radiology, University of California, San Diego, La Jolla, California
| | - Sean N Hatton
- Department of Psychiatry, University of California, San Diego, La Jolla, California.,Center for Behavior Genetics of Aging University of California, San Diego, La Jolla, California
| | - Christine Fennema-Notestine
- Department of Psychiatry, University of California, San Diego, La Jolla, California.,Department of Radiology, University of California, San Diego, La Jolla, California
| | - Daniel Rinker
- Department of Psychiatry, University of California, San Diego, La Jolla, California.,Department of Radiology, University of California, San Diego, La Jolla, California.,Imaging Genetics Center, Institute for Neuroimaging and Informatics, University of Southern California, Los Angeles, California
| | - Lisa T Eyler
- Department of Psychiatry, University of California, San Diego, La Jolla, California.,VA San Diego Healthcare System, Mental Illness Research Education and Clinical Center, San Diego, California
| | - Carol E Franz
- Department of Psychiatry, University of California, San Diego, La Jolla, California.,Center for Behavior Genetics of Aging University of California, San Diego, La Jolla, California
| | - Michael J Lyons
- Department of Psychology and Brain Sciences, Boston University, Boston, Massachusetts
| | - Michael C Neale
- Virginia Commonwealth University School of Medicine, Virginia Institute for Psychiatric and Behavioral Genetics, Richmond, Virginia
| | - Ming T Tsuang
- Department of Psychiatry, University of California, San Diego, La Jolla, California.,Center for Behavior Genomics, University of California, San Diego, La Jolla, California.,Institute for Genomic Medicine, University of California, San Diego, La Jolla, California
| | - Anders M Dale
- Department of Radiology, University of California, San Diego, La Jolla, California.,Department of Neurosciences, University of California, San Diego, La Jolla, California
| | - William S Kremen
- Department of Psychiatry, University of California, San Diego, La Jolla, California.,Center for Behavior Genetics of Aging University of California, San Diego, La Jolla, California.,VA San Diego Healthcare System, Center of Excellence for Stress and Mental Health, La Jolla, California
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