Study identifies genetic loci influencing face shape
A recent publication in the journal PLOS Genetics has begun to unravel the complex genetic background of facial variation amongst Europeans. An individuals genetic complement has always been known to influence their facial appearance. This can be seen clearly in the more similar appearance of monozygotic twins compared to dizygotic twins. More recently the implications of individual gene transcription patterns in facial variation have been explained through differences in cell migration, proliferation, differentiation and programmed death.
This study used a genetic technique known as genome-wide association studies (GWAS). GWAS look for correlations between a genotype and phenotype within a large population data set. In this case 48 separate facial phenotypes were studied using 3D MRI and 2D data alongside over 2.5 million single nucleotide polymorphisms (SNP’s).
Correlations were observed between 36 inter-landmark distances on the face and SNP’s within or close to (<10kb) 5 genes; PRDM16, PAX3, TP63, C5orf50 and COL17A1. These correlations between changes at a genetic level and changes in face shape were reproduced in a combination of separate studies, the analysis of separate data sets and through utilising alternative techniques.
This study takes a major step in the study of a complex human appearance trait such as face shape and begins to investigate the genetics behind the variation observed in populations. In the future, this work coupled with further studies using larger population samples will advance the understanding of normal and pathological variation in face shape. It may also provide clues as to the processes involved in sensory organ development.
As well as many practical applications, this study does have a Hollywood side to it. Future advances in this field may develop tools to predict facial appearance based upon DNA at crime scenes. Of course, this is the piece of info that the media jumped upon with some interesting titles such as ‘DNA analysis alone could potentially generate a picture of your face’ despite the paper stating “limited number of landmarks used in this study cannot capture the full range of the complex 3D shape variation in the face”. Just wish people would read the paper before writing about it.