Scientists discover genes that decide how human nose looks

A team of scientists at University College London (UCL) claimed to have found four genes that decided how a person’s nose looks.

The four genes, dubbed DCHS2, RUNX2, GLI3 and PAX1, affect human nose’s traits like width and ‘pointiness,’ which are responsible for a high level of variation in nose shapes among different populations.

The scientists discovered the genes after studying more than 6,000 individuals with a wide range of ancestry. They collected DNA samples from a total of 6,630 volunteers from Brazil, Colombia, Chile, Mexico, and Peru. Finally, they narrowed the DNA sample size to 5,958, consisting of Native American, African and European ancestry of both genders.

Kaustubh Adhikari, who led the study, said, “Finding out the role each gene plays helps us to piece together the evolutionary path from Neanderthal to modern humans. It brings us closer to understanding how genes influence the way we look, which is important for forensics applications.”

Facial features were also gauged using 3D computer simulations. Adhikari added that the findings of the study could help them further improve their understanding and expertise over forensic technologies.

The findings of the new research were reported in a recent issue of the prestigious journal Nature Communications.

As per the research paper published by the study team, “The researchers identified five genes which play a role in controlling the shape of specific facial features. DCHS2, RUNX2, GLI3 and PAX1 affect the width and pointiness of the nose and another gene — EDAR — affects chin protrusion.”

“Few studies have looked at how normal facial features develop and those that have only looked at European populations, which show less diversity than the group we studied. What we’ve found are specific genes which influence the shape and size of individual features, which hasn’t been seen before.

“Finding out the role each gene plays helps us to piece together the evolutionary path from Neanderthal to modern humans. It brings us closer to understanding how genes influence the way we look, which is important for forensics applications,” said the first author of the report, Dr Kaustubh Adhikari, UCL Cell & Developmental Biology.

“It has long been speculated that the shape of the nose reflects the environment in which humans evolved. For example, the comparatively narrower nose of Europeans has been proposed to represent an adaptation to a cold, dry climate. Identifying genes affecting nose shape provides us with new tools to examine this question, as well as the evolution of the face in other species. It may also help us understand what goes wrong in genetic disorders involving facial abnormalities,” explained Professor Andrés Ruiz-Linares UCL Biosciences.

According to a report in Washington Post by Ariana Eunjung Cha, “In the futuristic movie “Gattaca,” those in the ruling class are genetically engineered to be a physically perfect version of their parents. They are as thin and tall as models, with perfect cheekbones, square jaws and thick, glossy hair. Think of stars Uma Thurman and Jude Law. When the movie came out in 1997, this idea of “designer babies” was still far-fetched. DNA analysis was still in its early stages and the world was still years away from sequencing the first human genome, much less a particular gene’s function.”

The analysis involves scans of facial features of 6,000 volunteers in Latin America. According to DNA analysis, the group was estimated to be 50 percent European, 45 percent Native American and 5 percent African. Researchers measured nose-bridge breadth (the width in the middle of your nose), nose-wing breadth (the width at the bottom of your nose where it widens) and columella inclination (the incline of that section between the two nostrils), and found that they were associated with genes known as DCHS2, RUNX2, GLI3, PAX1 and EDAR.

A report published in the Discovery News said, “For example, the comparatively narrower nose of Europeans has been proposed to represent an adaptation to a cold, dry climate,” said study lead author Andrés Ruiz- Linares, a biologist at University College London. “Identifying genes affecting nose shape provides us with new tools to examine this question, as well as the evolution of the face in other species.”

Then, the team looked at the genomes of these people, and identified three genes known to drive bone and cartilage growth that also seemed to predict nose shape. Two genes, called GLI3 and PAX1, seemed to have a large effect on nostril width, while another, called DCH2, controlled nose pointiness. A fourth gene, called RUNX2, was associated with the breadth of the nose at the bridge.

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