title: Human Facial Shape and Size Heritability and Genetic Correlations.
abstract: The human face is an array of variable physical features that together make each of us unique and distinguishable. Striking familial facial similarities underscore a genetic component, but little is known of the genes that underlie facial shape differences. Numerous studies have estimated facial shape heritability using various methods. Here, we used advanced three-dimensional imaging technology and quantitative human genetics analysis to estimate narrow-sense heritability, heritability explained by common genetic variation, and pairwise genetic correlations of 38 measures of facial shape and size in normal African Bantu children from Tanzania. Specifically, we fit a linear mixed model of genetic relatedness between close and distant relatives to jointly estimate variance components that correspond to heritability explained by genome-wide common genetic variation and variance explained by uncaptured genetic variation, the sum representing total narrow-sense heritability. Our significant estimates for narrow-sense heritability of specific facial traits range from 28 to 67%, with horizontal measures being slightly more heritable than vertical or depth measures. Furthermore, for over half of facial traits, >90% of narrow-sense heritability can be explained by common genetic variation. We also find high absolute genetic correlation between most traits, indicating large overlap in underlying genetic loci. Not surprisingly, traits measured in the same physical orientation (i.e., both horizontal or both vertical) have high positive genetic correlations, whereas traits in opposite orientations have high negative correlations. The complex genetic architecture of facial shape informs our understanding of the intricate relationships among different facial features as well as overall facial development.
authors.affiliation: Human Medical Genetics and Genomics Program, University of Colorado School of Medicine, Aurora, Colorado 80045.
authors.forename: Joanne B
authors.initials: JB
authors.lastname: Cole
authors.affiliation: Department of Anatomy, Catholic University of Health and Allied Sciences, Mwanza, TZ-18, Tanzania.
authors.forename: Mange
authors.initials: M
authors.lastname: Manyama
authors.affiliation: Department of Anatomy and Cell Biology, University of Calgary, T2N 1N4, Canada.|McCaig Institute for Bone and Joint Health, Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, T2N 1N4, Canada.
authors.forename: Jacinda R
authors.initials: JR
authors.lastname: Larson
authors.affiliation: Department of Anatomy and Cell Biology, University of Calgary, T2N 1N4, Canada.|McCaig Institute for Bone and Joint Health, Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, T2N 1N4, Canada.
authors.forename: Denise K
authors.initials: DK
authors.lastname: Liberton
authors.affiliation: Human Medical Genetics and Genomics Program, University of Colorado School of Medicine, Aurora, Colorado 80045.
authors.forename: Tracey M
authors.initials: TM
authors.lastname: Ferrara
authors.affiliation: Human Medical Genetics and Genomics Program, University of Colorado School of Medicine, Aurora, Colorado 80045.
authors.forename: Sheri L
authors.initials: SL
authors.lastname: Riccardi
authors.affiliation: Department of Mathematics, Florida State University, Tallahassee, Florida 32304.
authors.forename: Mao
authors.initials: M
authors.lastname: Li
authors.affiliation: Department of Mathematics, Florida State University, Tallahassee, Florida 32304.
authors.forename: Washington
authors.initials: W
authors.lastname: Mio
authors.affiliation: Department of Orofacial Sciences, University of California, San Francisco, California 94143.|Department of Pediatrics, University of California, San Francisco, California 94143.|Program in Craniofacial Biology, University of California, San Francisco, California 94143.
authors.forename: Ophir D
authors.initials: OD
authors.lastname: Klein
authors.affiliation: Human Medical Genetics and Genomics Program, University of Colorado School of Medicine, Aurora, Colorado 80045.|Department of Mathematical and Statistical Science, University of Colorado Denver, Colorado 80202.
authors.forename: Stephanie A
authors.initials: SA
authors.lastname: Santorico
authors.affiliation: Department of Anatomy and Cell Biology, University of Calgary, T2N 1N4, Canada.|McCaig Institute for Bone and Joint Health, Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, T2N 1N4, Canada.
authors.forename: Benedikt
authors.initials: B
authors.lastname: Hallgrímsson
authors.affiliation: Human Medical Genetics and Genomics Program, University of Colorado School of Medicine, Aurora, Colorado 80045 richard.spritz@ucdenver.edu.|Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado 80045.
authors.forename: Richard A
authors.initials: RA
authors.lastname: Spritz
mesh_terms: D000293:Adolescent; D000886:Anthropometry; D002648:Child; D002675:Child, Preschool; D005145:Face / Q000033:anatomy & histology*; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D008445:Maxillofacial Development / Q000235:genetics; D010641:Phenotype; D019655:Quantitative Trait, Heritable; D055815:Young Adult
keywords: complex traits; facial shape; facial size; heritability; morphometrics