Heritability of the Human Craniofacial Complex.

Area of Science:

• Human genetics
• Anthropometry
• Craniofacial morphology

Background:

• Understanding genetic contributions to normal variation in human anatomical structures is key in modern morphology.
• The extent of genetic influence on craniofacial morphology remains largely undetermined.

Purpose of the Study:

• This study investigates the genetic underpinnings of normal craniofacial morphology.
• To quantify heritability across the craniofacial complex.

Main Methods:

• Utilized 75 linear and angular measurements from lateral cephalographs of 1,379 individuals from the Fels Longitudinal Study.
• Employed SOLAR (Sequential Oligogenic Linkage Analysis Routine) for maximum-likelihood variance components estimation, incorporating pedigree data.
• Simultaneously estimated trait means and covariate effects (age, sex, and their interactions).

Main Results:

• All measured craniofacial traits exhibited significant heritability, with estimates ranging from 0.10 to 0.60.
• The majority of heritability estimates were moderate.
• Similar heritability ranges were observed across the splanchnocranium, basicranium, and neurocranium.

Conclusions:

• Genetic influence on craniofacial morphology is substantial and comparable across different craniofacial components.
• Craniofacial traits possess significant heritability, making them valuable for population history and phylogeny reconstruction.
• Researchers conducting nongenetic studies should consider the genetic basis of craniofacial traits when designing studies and selecting samples.