Twin Zygosity DNA Test
A Twin Zygosity DNA Test is a conclusive way to determine if twins are identical or fraternal. Identical twins come from the same egg and same sperm so their DNA is exactly the same and thus are their features. For identical twins, the DNA profiles are an exact match.
Are They Identical or Fraternal?
Knowing whether twins are identical or fraternal is often difficult. Appearance alone can be deceiving, since identical twins do not always look exactly the same, and fraternal twins often appear very similar. Twins sometimes grow up without knowing for sure whether they are identical or fraternal.
Can’t the Doctor Determine Twin Zygosity Before or During Birth?
Identical twins often form in a single sac, sharing a placenta and amniotic membranes. An ultrasound during pregnancy can reveal whether twins share a placenta. If each has its own placenta, they are usually fraternal twins. But some identical twins will have their own placentas, and some will share, depending on when the fertilized egg split. So how it looks on an ultrasound is not definitive.
Identical twins have identical DNA
A Twin Zygosity DNA Test is a conclusive way to determine if twins are identical or fraternal. Identical twins come from the same egg and same sperm so their DNA is exactly the same and thus are their features. For identical twins, the DNA profiles are an exact match. Fraternal twins result from two separate eggs that are fertilized by two separate sperm. Though fraternal twins have some similarities, and are siblings, they do not share identical DNA. This test is very useful for parents who are keen on knowing the features of their twins and to serve as a valid legal proof regarding the identity of twins.