According to a report by published in the Polygenetic online journal on September 13, 2012, five genetic loci are responsible for the determination of facial morphology in humans. Since variations in facial features are the most prominent phenotypic variation in humans that are under genetic control, Liu F, van der Lijn F, Schurmann C, Zhu G, Chakra arty MM, et al carried out a genome association study for varied facial phenotypes in a population of ten thousand individual of European ancestry (2012).
The classification of the facial phenotypes was done using data obtained using three dimensional magnetic resonance (MRI) imaging and two dimensional portrait imaging. The researchers identified five genetic loci that are associated with some certain facial phenotypes. The researchers statistically assessed the facial phenotypes based on the statistical shape evaluation of facial landmarks that were obtained from the three dimensional resonance images (Liu F, van der Lijn F, Schurmann C, Zhu G, Chakra arty MM, et al, 2012).
The facial phenotypes used turned out to be were highly promising for genetic association because they showed a high heritability. The candidate genes identified in the study include PRDM16, TP63, COL17A, C5orf50 and PAX3. Three of the five genes identified as responsible for the determination of facial phenotype in humans have already been identified in previous studies as the genetic determinants of the craniofacial development and disease development in vertebrates. The other two genes are important players in the molecular mechanisms that govern the development of facial features in humans (Liu F, van der Lijn F, Schurmann C, Zhu G, Chakra arty MM, et al, 2012).
PAX3 gene was found to be responsible for influencing the location of the nasion. PAX3 was the gene that recorded the best results in influencing facial morphology among the five genes. The researchers also identified some common DNA variants associated with the gene, NSCL/P at positions 2p21, 13q31, 8q24 and 17q22 to be responsible for facial shape variations in a candidate gene. This whole study implied that some DNA variants in some genes that are essential for craniofacial development in vertebrates and contribute very little effect to the variation in the facial morphology in humans (Liu F, van der Lijn F, Schurmann C, Zhu G, Chakra arty MM, et al, 2012).
These studies indicate that there are some important links between some common variations in DNA and some facial variation in humans. These results suggest that a high level of heritability of the facial morphology Phenotypes can be explained by the presence of the a high number of common DNA variations that result in a mild individual effect on the size of the features on an individuals face (Liu F, van der Lijn F, Schurmann C, Zhu G, Chakra arty MM, et al, 2012).
These studies are very important in future studies aimed at identifying the genes that influence the development of facial morphology in humans. The findings of these studies have some implications in the prediction of the shape of the face using DNA. These genes could be used in the future in the creation of facial shapes from DNA obtained from crime scenes and therefore, increase the use of DNA as an investigative tool in crime analysis and forensics(Liu F, van der Lijn F, Schurmann C, Zhu G, Chakra arty MM, et al, 2012).
The findings of this study have shed light on the possible sources of genetic variation of the human face. These findings have huge implications on the understanding the development of facial pathologies, the physiology of the sensory organ systems in the body and a comprehension of the process of evolution in vertebrates. Further studies on these five genes that influence facial morphology could result in the creation of novel therapies and medications for facial pathologies and injuries(Liu F, van der Lijn F, Schurmann C, Zhu G, Chakra arty MM, et al, 2012).
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