This study examined three-dimensional facial images and genetic information from 2,329 healthy, unrelated people of European ancestry. Using information obtained from FaceBase (www.facebase.org), a public repository of craniofacial data launched in 2009 by the National Institute of Dental and Craniofacial Research, National Institutes of Health, in Bethesda, Maryland.
Using mathematical models, the investigators divided each face into 63 segments. They then performed a genomewide association study of each facial segment, which enabled them to observe genetic variations affecting parts of the face. The researchers identified 38 loci, 15 of which were replicated in an independent sample of 1,719 people. Four of the 15 loci were completely new; 9 were discovered previously and demonstrated consistent facial effects; and 2 were discovered previously with pleiotropic facial effects. The 15 replicated loci highlighted distinctive patterns of global-to-local genetic effects on facial shape. The loci also exhibited enrichment for active chromatin elements in human cranial neural crest cells, suggesting an early developmental origin of the captured facial variation. (publisher abstract modified)