Swiss perspectives in 10 languages

Predicting the future isn’t all in the genes

Being identical is no guarantee that twins will develop the same diseases Keystone

Two carriers of the same genetic mutation do not necessarily both develop the same disease. Whether this is due to genetics or environment is not clear, according to a study published on Monday in the scientific journal Nature Genetics.

Researchers from the University of Geneva’s medical faculty and the Swiss Institute for Bioinformatics studied the genetic informationExternal link of 400 pairs of monozygotic (identical) and dizygotic (fraternal) twins to try to determine whether the risk of developing a disease is related to genetics or environment or both.

Genetic information from the pairs of monozygotic twins, whose genomes are identical, was used to identify mutations that interact with the environment.

Information from the pairs of dizygotic twins, who shared only half of their genome but also were raised in the same environment, allowed researchers to separate purely genetic effects from environmental effects.

The researchers discovered that purely genetic (between genes) and environmental (between a gene and the environment) interactions both had a substantial influence on the way in which a person’s genetic composition is expressed.

“We have discovered that the genetic and environmental contexts of a mutation have a much greater influence on its expression in a given individual than we previously thought,” said the study’s lead author, Alfonso Buil.

However, the researchers also concluded that establishing a list of mutations present in a person’s genome is not sufficient to predict that person’s future health.

In compliance with the JTI standards

More: SWI certified by the Journalism Trust Initiative

You can find an overview of ongoing debates with our journalists here. Please join us!

If you want to start a conversation about a topic raised in this article or want to report factual errors, email us at

SWI - a branch of Swiss Broadcasting Corporation SRG SSR

SWI - a branch of Swiss Broadcasting Corporation SRG SSR