Genotyping and 3D Imaging Help Identify Genes That Influence Facial Appearance

MedicalResearch.com Interview with:

Seth M. Weinberg, PhD

Dr. Seth Weinberg

Seth M. Weinberg, PhD
Assistant Professor, Department of Oral Biology
Assistant Professor, Department of Anthropology
Director, CCDG Imaging and Morphometrics Lab

MedicalResearch.com: What is the background for this study?

Response: Scientists have long recognized that aspects of facial appearance have a genetic basis. This is most obvious when we look at the faces of people in the same family.  It is also well known that mutations in certain genes can result in syndromes where the face is affected.  However, very little is known about how specific genes influence the size and shape of normal human facial features.  To date, only a handful of studies have looked at this question, and while these studies have reported several interesting results, only a small number of genes have so far been linked to normal variation in facial features.  The primary goal of our study was to test for evidence of association between detailed facial measures derived from 3D images and common genetic variants spread across the entire genome.  We also attempted to independently replicate some of the findings from previous studies.

MedicalResearch.com: What are the main findings?

Response: We found statistically significant associations involving five facial measurements in seven different regions of the genome. These measures involved the width of the face and nose, the distance between the eyes, and the projection (or depth) of the nose and upper face.  Although we do not know precisely which genes are involved (because regions may contain multiple genes), several of the genes in the associated regions are known to either play a role in genetic syndromes where the face is affected or be expressed in the developing face.  These include genes like ALX3, HDAC8, MAFB, and PAX1.  Another important finding from our study was that we were able to replicate several previously reported genetic associations, most notably for measures involving the nose.

MedicalResearch.com: What should readers take away from your report?

Response: The combination of advanced 3D imaging, detailed measurement methods, and high-throughput genotyping has enabled us to begin mapping the genes that influence facial appearance. By applying these methods, we were able to identify several novel genetic associations involving features that give rise to our highly unique facial identities, such as the shape of our noses or how far apart our eyes are spaced.  Such findings could have far reaching implications in the future for disciplines ranging from paleoanthropology to forensics to orthodontics.

MedicalResearch.com: What recommendations do you have for future research as a result of this study?

Response: Human facial morphology is highly complex. We are only at the very beginning of attempting to understand how genes influence our facial features.  For future studies, it is critical that we focus on ways to extract the rich information contained in faces.  This will require moving beyond simple linear measurements.  Likewise, we hypothesize that most genes that influence facial shape will have very small effects.  This means that very large sample sizes will be needed to detect these genes.  Collaborative efforts involving many research groups sharing data will be necessary to achieve sufficient sample sizes.

Citation:

Shaffer JR, Orlova E, Lee MK, Leslie EJ, Raffensperger ZD, Heike CL, et al. (2016) Genome-Wide Association Study Reveals Multiple Loci Influencing Normal Human Facial Morphology. PLoS Genet 12(8): e1006149. doi:10.1371/journal. pgen.1006149

Note: Content is Not intended as medical advice. Please consult your health care provider regarding your specific medical condition and questions.

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Last Updated on August 31, 2016 by Marie Benz MD FAAD