Research reveals that identical twins may not be genetically identical

Researchers in Iceland conducted a study and inferred that identical twins have genetic differences that begin at the early stages of embryonic development.

This study has been used by scientists to examine effects of nature vs nature as the accepted view is that the twins share the same genes, behavior and physical differences due to external factors.

The latest research published in the journal Nature Genetics denies the above acceptance.

Identical twins are produced from a single, fertilized egg called the zygote. Cell divisions lead to mutations in an embryo. This type of genetic difference had previously not been accounted for in identical twins.

The study conducted for over four years, consists of a team of Icelandic researchers at DeCode Genetics, a Reykjavík  biopharmaceutical company. The study found that twins have genetic differences that begin in the early stages of embryonic development, be it monozygotic or identical.

The authors even found that on an average, twins differed by 5.2 early developmental mutations and some startling differences in the genetic mutations of identical twins was discovered.

The study further raised questions like why when identical twins develop a disease, it is attributed to external factors?