Specifically, the study 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. 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. The current study's significant estimates for narrow-sense heritability of specific facial traits ranged from 28 to 67 percent, with horizontal measures being slightly more heritable than vertical or depth measures. Furthermore, for over half of facial traits, >90 percent of narrow-sense heritability can be explained by common genetic variation. The study also found high absolute genetic correlation between most traits, indicating large overlap in underlying genetic loci. Traits measured in the same physical orientation (i.e., both horizontal or both vertical) have high positive genetic correlations; whereas, traits in opposite orientations had high negative correlations. The complex genetic architecture of facial shape informs the understanding of the intricate relationships among different facial features as well as overall facial development. (Publisher abstract modified)
Human Facial Shape and Size Heritability and Genetic Correlations
NCJ Number
252052
Journal
Genetics Volume: 205 Issue: 2 Dated: February 2017 Pages: 967-978
Date Published
February 2017
Length
12 pages
Annotation
This study used advanced three-dimensional imaging technology and quantitative human genetics analysis to estimate narrow-sense heritability, which is 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.
Abstract