Human Facial Shape and Size Heritability and Genetic Correlations

Area of Science:

• Human genetics
• Anthropometry
• Quantitative genetics

Background:

• Facial features are unique and distinguishable, with familial similarities suggesting a genetic basis.
• Little is known about the specific genes influencing facial shape differences.
• Previous studies have estimated facial shape heritability using various methods.

Purpose of the Study:

• To estimate narrow-sense heritability, heritability from common genetic variation, and genetic correlations for 38 facial shape and size measures.
• To investigate the genetic architecture of facial traits in African Bantu children.

Main Methods:

• Utilized advanced three-dimensional imaging technology and quantitative human genetics analysis.
• Applied a linear mixed model of genetic relatedness to estimate variance components.
• Analyzed 38 measures of facial shape and size in normal African Bantu children from Tanzania.

Main Results:

• Narrow-sense heritability estimates for facial traits ranged from 28% to 67%, with horizontal measures being more heritable.
• Common genetic variation explained over 90% of narrow-sense heritability for more than half of the facial traits.
• High genetic correlations were observed between most traits, indicating shared genetic loci, with correlations varying by measurement orientation.

Conclusions:

• The complex genetic architecture of facial shape is significantly influenced by common genetic variation.
• Facial traits exhibit substantial overlap in their underlying genetic loci.
• Understanding facial trait heritability provides insights into facial development and feature relationships.