Twin zygosity testsTwin zygosity tests are for parents of twins or twins interested in knowing if they are identical (monozygotic) or fraternal (dizygotic). The results of the test are usually used to satisfy personal curiosity, but there can be health advantages as well. Identical twins, because their genetic makeup is exactly the same, can always act as organ, tissue, or blood donors for each other. Identical twins are also likely to develop the same genetic disorders; if a disorder is exhibited in one twin, the it is likely that the other twin will develop it as well.

A twin zygosity test will help parents or twins themselves better prepare for the future, providing additional genetic information and medical history.