Amy Middleton
Amy Middleton is a Melbourne-based journalist.
The shapes and traits that make each human face unique – such as the distance between our eyes and size of our nose – are dependent on specific sets of genes, and a new study has confirmed where they are.
The work, published in PLOS Genetics, may help reconstruct faces from DNA samples.
While a flick through the family album strongly suggests that genes affect our looks, the exact regions of the genome responsible for our face shapes had not been previously identified.
To find them, a team led by John Shaffer at the University of Pittsburgh in Pennsylvania, US, analysed the entire genome of more than 3,000 individuals to find links between certain gene regions and common facial traits.
“Numerous lines of evidence point to a genetic base for facial morphology in humans, yet little is known about how specific genetic variants relate to the phenotypic expression of many common facial features,” the researchers write.
Some 3,118 healthy individuals living in the US and with European ancestry had their faces scanned in 3-D. The researchers then analysed a set of 20 different facial traits across that sample, which included measurements and sizes across different areas of the face.
These traits were then compared against nearly a million variations across the genome to find any associations.
The team found seven genome-wide associations for five different facial traits, including nose width and length, and upper facial depth – that is, the distance from the middle of the eyes to the ear.
Some of the gene regions were previously thought to play a role in syndromes or defects that affect facial traits, such as cleft lip and palate.
“Such findings can provide insights into the role genes play in the formation of the face and improve our understanding of the causal factors leading to certain craniofacial birth defects.”
The researchers emphasise that they’ve only identified a fraction of the genes that contribute to our facial development, and more research is needed – with many more people – to widen the map.
But they hope this new information will contribute to a wider understanding of craniofacial development, which could help predict how human faces might evolve in the future and help reconstruct face shapes from DNA.
