Study Identifies Genes Associated with Facial Features
The face is a very complex structure, requiring much genetic input to be put together. That is why it is impressive that researchers at Erasmus Medical Center in Rotterdam, Holland, recently discovered and revealed five genes that help control the width of the human face. Although hundreds of genes involved in shaping the face remain to be identified, the findings represent an early step toward facial reconstruction with DNA.
A couple of years ago, researchers at the aforementioned center wondered whether it would even be possible to identify which versions of a gene would lead to a broad nose or a wide forehead. If it was, they reasoned, then eventually a computer program could build a composite of an individual’s face based on DNA. This would be a groundbreaking advancement. If you can get into the genetic shape of the nose, eyes, lips and so forth, with a program it could be of great value.
Identifying the Genes
Before the researchers could start identifying the genes, they needed to break down the face into discrete, measurable features that could be assessed in each individual. Looking at MRI images, they picked out nine landmarks on the face. The distances between different pairs of landmarks in a given face were traits for the team to evaluate — for example, the spacing between the eyes or the distance from the tip of the nose to its base.
Once this was done, the research team examined the DNA of five groups of people to see whether any particular variants of a gene were associated with each trait. Each group contained between 545 and 2,470 individuals. Three other groups of people were subsequently evaluated as well, as a way to independently test the genetic correlations derived from the first five groups.
According to their research, published in PloS Genetics, five genes emerged as important to facial features. The genes influenced traits such as the width of the face, the distance between the eyes, and how far the nose sticks out.
One gene, called PAX3, had already been linked to the shape of the face in children, giving the research team confidence that their approach to finding relevant genes worked. Other researchers had previously tied two of the other genes, one on chromosome 2 and one on chromosome 3, to facial problems such as a cleft lip or malformed jaws. The final two genes were, on the other hand, newly connected to facial development.
The First Step of a Long Journey
Unfortunately, on the downside, the work confirms what many had suspected; there are no common variants with large effects. It is, in fact, likely that there are many hundreds or thousands of these variants, each having a small influence on the face.
That many more genes are involved, each contributing a little bit toward building the face, means that this is just the first step of a long journey. The findings are certainly very exciting, but require a lot more research, simply because our DNA is so complex. The good news, on the other hand, is that the researchers behind the findings are determined to hunt for other genes.
While the variability in this particular study only explains a very tiny proportion of the variability in facial shape, the team is optimistic that within two to five years, some form of facial reconstruction with DNA will be possible. This could, help patients in need of advanced facial reconstruction.