A recent study conducted by deCODE Genetics, a company that specializes in identifying genes through population-based studies, has found that genetic differences can occur in identical twins. The study, which examined 387 pairs of identical twins, aimed to determine the extent to which the DNA of individuals differs and whether these differences are present in both somatic and germ cells. The results showed that genetic differences can arise in identical twins due to mutations in the cell lines of a twin embryo, which can occur in the early stages of development in the womb. The study found that approximately 15% of monozygotic twins have genetic differences caused by mutations, with the number of mutations ranging from one to a maximum of 100 gene alterations.
Until now, it was believed that identical twins share the same genetic makeup. However, the study’s findings suggest that mutations in the womb can cause genetic differences between siblings. The study’s lead researcher, Hakon Jonsson, explained that the embryos separate in the womb just a few days after fertilization, providing enough time for mutations to occur. The study’s results have important implications for medicine, particularly in the field of twin research, where the comparison of identical twins is used to determine the hereditary factors of various diseases.
The study’s findings also shed light on the timing of mutations in identical twins. If both somatic and germ cells of a twin have a mutation, it suggests that the genetic alteration occurred in the early stages of embryonic development, specifically during the separation of the germ cell line from the somatic cell line. The study’s results challenge the assumption that mutations in monozygotic twins are rare, highlighting the need for further research in this area.
