Identical Twins Are Not So Identical, Study Reveals

A recent research has revealed that genetic mutations between identical twins begin very early and that they differ by an average of 5.2 early mutations. This development contributes fresh insight in the nature versus nurture debate.

The Role of Genetics

Identical twins have long been thought to have minimal genetic differences due to the fact that unlike every other person, monozygotic twins (identical twins) are formed from a single fertilized egg that breaks into two. This has made them assume heightened significance to researchers who are interested in finding out the roles of environmental factors towards physical or behavioral differences.

 

However, this new research suggests that the role of genetics towards the formation of these variances has been largely underestimated. The research was published in the journal Nature Genetics.

 

According to the co-author of the paper and the head of Iceland’s deCODE genetics, a subsidiary of the US pharmaceutical company Amgen, Kari Steffanson, “The classic model has been to use identical twins to help you to separate the influence of genetics versus environment in analysis of diseases.”

 

Explaining further, he said, “So if you take identical twins raised apart and one of them developed autism, the classic interpretation has been that that is caused by the environment. But that is an extraordinarily dangerous conclusion.” He added that the disease could possibly be caused by an early genetic mutation in one twin and not the other.

A Clear and Important Contribution

The research has been praised as “a clear and important contribution” to medical research by Jan Dumanski, a geneticist at Uppsala University, Sweden. He opined that when trying to investigate the influence of nature and nurture to human behavior, “we have to be very careful when we are using twins as a model.” Jan Dumanski was not involved in the new paper. Another psychologist, Nancy Segal, hailed the research as being, “heroic and really significant.”