The reason all human faces are unique

Pam Baker / 27 July, 2017 / General Epigenetics News

Researchers in France and Switzerland pondered the question of why human faces do not all look the same. After all, animals of the same species have identical features. So why, the researchers wondered, aren’t human faces following that same cookie-cutter pattern?

Why does one person have big lips, another a high forehead, another a pointed chin? And, why do the variances of so few features – mouth, nose, eyes, chin, cheeks, forehead, and ears-- seem endless to the point that human faces are each unique?

The Friedrich Miescher Institute for Biomedical Research team discovered that epigenetic mechanisms called histone modifications do most of the face shaping work that makes you look like you.

The story begins with neural crest cells; the cells that specialize in building most of the bones and cartilage that form a human face. These cells have plasticity which essentially means that they are not rigid and can be shaped and molded by the histone modifications until the design of the face is settled.

In other words, the DNA inside these cells determines the general face shape, but the cells are also open to outside input for the final touches. Think of it this way, DNA is generally going to put a nose in the facial area reserved for noses, but epigenetic mechanisms sculpt many of the nose’s features, such as an upward tip, a flat nose bridge, wide nostrils, or a pronounced bump on the nose ridge.

DNA forms the mold of the face, epigenetic mechanisms add character and distinction to the features.

If you want the full take on the science and research involved, read the paper "The Epigenetics of Face-Making" in the journal, Science.

Otherwise, suffice it to say that epigenetics is the study of the mechanisms that switch genes on and off. It has to do with the expression of genes, in other words, and not the deletion, modification, or addition of genes. This particular discovery is on how genes are switched on and off by mechanisms responding to the environment to form a unique human face. It is not an exercise in vanity because this information sheds light on how facial birth defects happen too.











Consider new research, this time by the University of Bristol, on the largest study of cleft lip and/or palate in the world, known as the Cleft Collective. Those researchers found that epigenetics could help diagnose different types of cleft.

"Our study is a promising first step in exploring the potential role of epigenetics in causing clefts. It also highlights that epigenetic data might be useful in diagnosing different types of cleft,” Dr Gemma Sharp, Lecturer in Molecular Epidemiology in the School of Oral & Dental Sciences and a member of the Cleft Collective, said in an article in Medical Xpress.

You can find a scientific explanation of this research in a paper in Clinical Epigenetics, the official journal of the Clinical Epigenetics Society.

In the future, plastic surgeons may find a way to use this and additional epigenetic data to build pretty faces. However, preventing the formation of facial defects in the womb will likely become routine.

For now, it’s a giant step forward to have the means to detect the presence of cleft palate in a newborn earlier.

"Cleft palate rarely shows up on ultrasound and can be difficult to diagnose after birth, so better diagnosis could help to reduce the rate of poor outcomes associated with late diagnosis,” says Dr. Sharp.

In any case, epigenetics is helping us all face a brighter, better future in myriad individual ways.