In 2013, twin brothers were arrested and both charged with a rape in Berkshire because the police were unsure which one the DNA evidence came from. One twin was eventually convicted, and charges dropped against the other because mobile phone evidence placed him elsewhere.
Identical twins have matching DNA, so a case based solely on such evidence would have failed because prosecutors would be unable to isolate who was responsible for the alleged rape.
However, technology has advanced since and we are now able to distinguish between identical twins through specialised DNA profiling techniques.
Identical twins are genetically identical, which means that they are formed from the same fertilized egg. However, even though identical twins share the same genetic material, they are not entirely alike. There are subtle differences in their physical appearance, behaviour, and personality traits. This is where zygosity testing comes in.
What is Zygosity?
Zygosity refers to the genetic similarity between two individuals who have developed from the same fertilized egg. In the case of identical twins, they have the same zygosity because they have developed from the same egg. On the other hand, fraternal twins, also known as dizygotic twins, have a different zygosity because they have developed from two separate eggs.
DNA testing is a highly accurate method of determining zygosity, and it has become the gold standard for zygosity testing. DNA testing is the most accurate method of determining zygosity. This test involves analysing the DNA of the twins to determine whether they are genetically identical or not. The DNA is extracted from cheek cells, and then analysed using various techniques to provide valuable information about the genetic identity of the twins.
Zygosity testing is an important step for families with identical and non-identical twins. It helps to establish the genetic identity of the twins. This can be useful in cases where there is a need to establish legal or medical paternity.
Cellmark has been providing confidential, conclusive, court approved DNA sibling testing to members of the public, local authority Children's Services teams, government departments and the legal profession for nearly four decades. When you choose Cellmark you can be sure your test will be carried out with the care, accuracy and precision it deserves.
You can complete your DNA sibling testing registration using our online registration service or by calling Cellmark's Customer Services team. Cellmark will assist with arranging a convenient time for an appointment for the DNA samples to be taken.