Identical twins, or monozygotic twins, are often regarded as genetic clones due to their origin from a single fertilised egg.
But do identical twins have the same DNA? While they have nearly identical genetic compositions, scientific research uncovers fascinating nuances that differentiate them.
In this article, we’ll explore the fertilisation process that leads to the creation of identical twins and reveal the truth behind whether their DNA is truly the same.
How Are Identical Twins Formed?
Biologically, identical twins are formed when one fertilised cell splits into two separate embryos during the primary stages of development. Since they originate from the same zygote, they inherit the same DNA from their parents. This shared genetic foundation explains why identical twins are so similar and why they often exhibit comparable traits, ranging from physical characteristics to their susceptibility to various medical conditions.
Do Identical Twins Always Share the Same DNA?
Although identical twins mostly share the same DNA, this is not always the case. While their genetic makeup is almost identical, small differences can still arise. These differences are primarily caused by mutations that occur during cell division and replicate throughout the development process.
Research has also revealed variations in the number of copies of certain genes, even in identical twins. Although these differences are rare, they can be significant, providing evidence that no two individuals, including monozygotic twins, are exactly the same.
Another important factor is epigenetics, which studies how environmental influences such as stress, prenatal conditions, and diet affect gene expression. While epigenetics doesn’t alter the DNA sequence itself, it can change how genes are activated or deactivated. This can lead to variations in traits, behaviors, and even health outcomes in twins.
Additionally, fraternal or dizygotic twins do not share the same DNA, as they arise from two distinct sperm cells fertilising two distinct eggs. Unlike identical twins, fraternal twins share only about 50% of their DNA, similar to any other sibling. In contrast, identical twins start with the same DNA, but changes can occur due to mutations or epigenetic factors, making them not completely identical.
Conclusion
While identical twins have the same DNA foundation, subtle differences arise due to small mutations and environmental factors.
Even though identical twins share nearly identical DNA, subtle genetic and environmental differences can influence their health in unique ways. This highlights the importance of personalised health insurance coverage. Just as no two individuals—whether twins or not—are exactly the same, health insurance plans must be personalised to fit the unique needs of each person.
Disclaimer: The information provided in this blog is for educational and informational purposes only. It is not intended as a substitute for professional advice, diagnosis, or treatment. Please consult your general physician or another certified medical professional for any questions regarding a medical condition. Relying on any information provided in this blog is solely at your own risk, and ICICI Lombard is not responsible for any effects or consequences resulting from the use of the information shared.