Whether you’ve got a button nose, a hook nose, or a Roman nose, you can blame a specific group of five genes for the shape of your honker, according to a new study that appears in the journal Nature Communications.
When it comes to appearances, humans are probably the most diverse species on the planet, coming in all shapes and sizes. This goes as much for our faces as our bodies, and of course one of the most prominent items on the facial landscape is the schnoz.
Differences in nasal design are thought to be driven by a number of evolutionary adaptations, such as the need for nostrils of a particular size in order to control the volume and temperature of inhaled air. The fact that humans tend to recognize each other by sight rather than smell (in most cases!) is another key driver of our wildly varying facey bits.
Surprisingly, these enormous differences in nose shape and size are controlled by a rather small number of genes, which, according to the study authors, encode for specific characteristics such as nostril width, “pointiness,” and the inclination of the bridge of the nose.
To discover this, the researchers looked at photographs of 6,275 people from across Latin America, cross-referencing these images with a full analysis of their genomes, obtained via a DNA sample. In particular, the study authors analyzed 14 different facial traits, seeking out any genetic similarities between people with similar features.
Amazingly, the researchers were able to pinpoint five genes that seem to code for specific nasal traits. For instance, a gene called DCHS2 – which plays a role in controlling cartilage formation – was found to have a major influence over the pointiness of a person’s nose. Another gene, called PAX1, was identified as a driver of nostril breadth, while RUNX2, which is involved in bone growth, is vital for nose bridge width.
This knowledge could have major implications for the treatment of inherited facial deformations. Conditions such as Campomelic Dysplasia, for instance, are associated with a range of craniofacial defects, and are thought to be caused by mutations in genes controlling the development of cartilage.