Genetic examination of Zygosity.

The DNA test makes it possible to determine uniquely whether the twins are single(monozygotic) or bivalent (dizygotic).

Analysis methods Availability Number of genes Test code Retail Price
PCR 3 – 4 weeks GHC 034 £ TBA

Detailed information

Approximately two-thirds of all twins are bivalent. Determining the zygosity of twins is not easy. If twins of different sexes were born, the twins are very likely to be two-legged. Single-sex twins are of different sex only in isolated cases when a genetic mutation occurred during intrauterine development.

The examination is appropriate if:

  • You are wondering if your twins are single or double
  • It is necessary to verify the possibility of donating organs between twins
  • You would like to know the risks of genetically-related diseases in one of the twins
Although the reason for testing is often curiosity or research purposes, knowing this can also be crucial from a medical point of view, as, for example, single-sex twins can give organs in certain situations or estimate the risk of genetic disease in one of the twins.

Who is the test suitable for?

The test is designed for twins that are unclear whether they are monozygotic or bivalent (dizygotic). Examinations can be performed in twins of any age and gender, as genetic information is invariable throughout life.

What can this test reveal?

In DNA testing of twins (zygosity) of twins, we investigate 15 DNA segments called STR plus markers, another section to determine the sex of the samples. By comparing the DNA profiles obtained, the test reliably determines whether the twins are single (monozygotic) or bivalent (dizygotic).

How does the test work?

Genetic examination is performed from your DNA, which can be obtained by swabbing from the oral cavity (buccal wiping of the inside of your mouth cheek - DNA isolation from oral mucosal cells). You can take the sample yourself in the comfort of your home and send it to our lab, or have your collection taken by your GP.

How is the test done?

You can order the test from attending your Doctor/GP, private clinic or online at ghcgenetics. Once you have signed the informed consent form, either a swab of your mouth will be taken or a blood sample will be collected. Once the genetic analysis is finished, you or your Doctor/GP will receive a report with the results and based on these he/she will recommend suitable preventive measures.