AR&D and APH researchers Jenny van Dongen (assistant professor at VU Amsterdam) and Dorret Boomsma (professor Biological Psychology at VU Amsterdam) discovered that identical twins have a unique epigenetic profile. Up until now the origin of identical twins was a complete mystery.

The researchers found epigenetic differences between identical twins and others. These differences are not located in the DNA, but in the methyl groups surrounding the DNA. These small molecules can switch specific genes in the DNA on or off, and thereby influence how the DNA is expressed. Boomsma and van Dongen found 834 locations in the DNA where the methyl groups of the identical twins differed from the general population.

These findings are interesting to get a better understanding of birth defects, especially those imprinting disorders that show an overrepresentation of identical twins among the patients. Moreover, the epigenetic profile offers possibilities to estimate whether someone is an identical twin or not.

The study, published in Nature Communications, analyzed data from the Netherlands Twin Register. Additionally the twin registries from Great-Britain, Finland and Australia were involved in this study.

For a short summary, watch the NOS News broadcast of september 28, 2021 (min. 20)

Read the news (in Dutch) in de Volkskrant.