In the largest genome-wide association study of its kind, an international team of researchers led by scientists at the University of Pittsburg have identified dozens of genetic associations for detached earlobes, a seemingly simple trait that is much more complex than once thought and could yield insights into serious genetic conditions.
Beyond revealing more about the complex genetics behind whether a person’s earlobes are attached or not, the findings also could give insights for those working to treat genetic conditions that impact facial-cranial development.
“Sometimes the genetics of a fairly simple trait are actually quite complex,” said lead author John R. Shaffer, Ph.D., assistant professor in Pitt Public Health’s Department of Human Genetics, and the Department of Oral Biology in Pitt’s School of Dental Medicine. “By understanding that complexity, we can work toward treatments for genetic conditions, several of which have distinct facial features that involve the earlobe, including Mowat-Wilson Syndrome.”
Published in the American Journal of Human Genetics, the large-scale genetic study was an international collaboration with contributions from investigators in the United Kingdom and China and included data from the 23andMe.
In all the study identified 49 different genetic associations, looking at data from a diverse group of more than 74,000 people with European, Chinese and Latino ancestry. More than 65,000 of those included in the study are 23andMe customers who consented to participate in research. Those large numbers helped to dramatically increase the statistical power of this study, making it the largest genetic association study of earlobe attachment to date.
The researchers started with a smaller group of 10,000 participants and were able to identify six genetic variants strongly associated earlobe attachment. When the analysis was broadened to include the 23andMe participants, researchers replicated those six variants along with 43 others.
“This is the unique power of 23andMe’s research platform — to quickly and easily make genetic discoveries across a broad variety of phenotypes,” said Joyce Tung, 23andMe’s vice president for research.
This kind of research can uncover “biology that might never otherwise see the light of day because it doesn’t obviously meet the priorities for research funding,” Joyce said. “And yet, important insights can still be drawn even from seemingly insignificant traits.”