A practical and simple case of explaining genetics is to compare the earlobes with that of our parents. However, a new study from the University of Pittsburgh has revealed that this explanation may be more complicated than we thought. This is because at least 49 different genes have been found to interact in creating the lobe .
According to lead research author John R. Shaffer , “Sometimes the genetics of a fairly simple trait are actually quite complex. By understanding that complexity, we can work towards treatments for genetic conditions, many of which have distinct facial features affecting the earlobe, including Mowat-Wilson syndrome, which can cause cupped ears with protruding lobes. “
The international collaboration of China and the United Kingdom has been key to the results in the study, since the sample size was much larger and the ethnic diversity of the participants provided a greater depth of genetic information.
The way of working has consisted of the combination of two different research methods. One on a large scale , getting results from an extensive network, but without detail. And another one that is smaller and with more depth of nuances.
First, the team investigated a sample of just under 10,000 participants who, in addition to providing genetic data, underwent screening to determine whether their lobes were attached, separated or partially attached. The subjects also provided some medical history and were examined for a family history of birth defects.
The team later partnered with an American personal genetics company to include 65,000 clients who agreed to participate in the research. This fact drastically increased the statistical power of the study. In the latter case, the volunteers provided self-reports on their earlobe status by limiting the response to attached or detached.
With the results of the first sample , that of the reduced group, the researchers were able to identify six genes that largely determined the attachment of the earlobe.
After expanding the analysis with the American company, it was shown that those same six genes were again strongly involved in the fixation of the earlobe. However, 43 other genes were added to these. Therefore, in total we speak of almost fifty genes that influence the union process .
The ins and outs of genetics
“We have these 49 genes that we know affect earlobe attachment, but we don’t know how they work together or interact with each other,” according to Feingold , one of the study’s collaborators. “Understanding that is the next step,” he said.
In this sense, it is therefore not so easy to explain the ins and outs of genetics using the earlobe as a practical case. Even a seemingly simple inherited trait has been shown to carry a complex and fascinating interplay of genes that scientists are only just beginning to understand.
References: ‘Multiethnic GWAS Reveals Polygenic Architecture of Earlobe Attachment’. John R. Shaffer. (2017). American Journal of Human Genetics. DOI: http://dx.doi.org/10.1016/j.ajhg.2017.10.001
