Variation in facial shape is an easy way to explain phenotypes in humans to people who don't understand biology all that well. Monozygotic twins have almost identical faces and siblings usually have more similar faces than unrelated people, implying our facial morphology is under genetic regulation - but still little has been known about the genetic basis of normal human facial morphology. 

A new study was carried out on behalf of the International Visible Trait Genetics (VisiGen) Consortium with almost ten thousand individuals of European descent from several countries. Phenotyping of facial shape features was based on landmark data obtained from three-dimensional head magnetic resonance images (MRIs) and two-dimensional portrait images to map facial landmarks, from which facial distances were estimated. The researchers then applied a genome-wide association (GWA) approach, with independent replication, to finding DNA variants involved in facial shapes in almost 10,000 individuals.

They identified five independent genetic loci associated with different facial phenotypes, suggesting the involvement of five candidate genes — PRDM16, PAX3, TP63, C5orf50, and COL17A1 — in the determination of the human face.

Nine facial landmarks extracted via image registration tools from 3D MRIs. An MRI of one of the authors (MK) is used for illustration. A, with the landmark for left zygion (ZygL) highlighted, where a clipping plane was used to uncover the bone; B, with the landmarks for left (EyeL) and right pupils (EyeR) highlighted, where a clipping plane was used to uncover the vitreous humor; C, with the four nasal landmarks highlighted, including the left alare, nasion (Nsn), pronasale (Prn), and subnasale (Sbn). Source: PLoS Genetics. doi:10.1371/journal.pgen.1002932.g001

Three of the five genes identified have been implicated previously by other approaches in vertebrate craniofacial development and disease; of these three, one was reported to be involved in facial morphology in a GWA study on children published earlier this year. The remaining two genes potentially represent completely new players in the molecular networks governing facial development. 
They also established links between common DNA variants previously associated with NSCL/P at 2p21, 8q24, 13q31, and 17q22 and normal facial-shape variations based on a candidate gene approach. 

Professor Manfred Kayser from the Erasmus University Medical Center, in Rotterdam, leading author of the study, said, "These are exciting first results that mark the beginning of the genetic understanding of human facial morphology. Perhaps some time it will be possible to draw a phantom portrait of a person solely from his or her DNA left behind, which provides interesting applications such as in forensics. We already can predict from DNA certain eye and hair colours with quite high accuracies."

Citation: Liu F, van der Lijn F, Schurmann C, Zhu G, Chakravarty MM, et al. (2012) A Genome-Wide Association Study Identifies Five Loci Influencing Facial Morphology in Europeans. PLoS Genet 8(9): e1002932. doi:10.1371/journal.pgen.1002932