By Sola Ogundipe

Identical siblings are used to sharing a lot with their twin, including their DNA, but new research suggests all identical twins share a common signature of twinhood, not in their DNA, but on it.

This signature is part of the epigenome, chemical markers that dot many spots along DNA and influence the activity of genes without altering their sequence. 

Identical twins everywhere largely share a specific set of these marks that persists from birth to adulthood, researchers report in Nature Communications.

These shared epigenetic tags could be used to identify people who were conceived as identical twins but lost their sibling in the womb or were separated at birth.

The research sets the groundwork for scientists to better understand “what might cause a fertilized egg to split and form identical twins.

Researchers know that identical twins form after a fertilized egg, called a zygote, somehow splits into two embryos during development. But why this cleavage happens remains unknown.

For most part, identical twins don’t run in families, and they occur at roughly the same rate worldwide — about 3 to 4 per 1,000 births.

With no clear genetic or environmental cause, the prevailing hypothesis is that identical twins arise at random.

Vanguard News Nigeria