DNA Twin Test

A DNA Twin Test (also called a Twin Zygosity Test) definitively determines whether twins are identical (monozygotic) or fraternal (dizygotic). This test is valuable for Canadian families when hospital records are unclear or inconsistent, as visual assessment at birth isn’t always accurate, especially with same-sex twins who look very similar. Beyond curiosity, knowing twin type can be medically important for understanding health risks, organ compatibility, and genetic predispositions. Many adult twins also seek testing to confirm their twin status after years of uncertainty.

Our DNA Twin Test provides 100% definitive results, not just statistical probabilities. The test analyzes up to 27 genetic markers through dual-process testing in our accredited Canadian laboratory. Identical twins share 100% of their DNA (having developed from a single fertilized egg that split), while fraternal twins share approximately 50% (like non-twin siblings). This clear genetic distinction allows us to provide completely conclusive results, unlike some of our other relationship tests that work with probabilities.

If test participants live in different cities or countries, we can split the DNA test kit and ship components to separate addresses. Each kit part is individually barcoded for secure tracking, and testing begins once all samples reach our laboratory.

To request a split kit, include the following in the “Additional Information” section at checkout:

“Please send Person A’s kit to [Name, Address] and Person B’s kit to [Name, Address].”

Note: Additional shipping fees apply for multi-address orders.

Hospital determinations of twin type are often based on visual assessment or examination of the placenta and amniotic sac during birth. However, in approximately 40% of identical twin pregnancies, the twins develop with separate placentas and amniotic sacs (just like fraternal twins), leading to incorrect classification. Conversely, fraternal twins can sometimes look remarkably similar. Only genetic testing can provide definitive confirmation of whether twins are identical or fraternal.

No, the DNA test kits do not have an expiration date and can be stored indefinitely before sample collection. However, once a sample is collected, it’s recommended to send the kit back to our laboratory for testing within 3 months to ensure the best results.

The collection process is extremely simple and painless. Your kit includes easy-to-use cheek swabs (similar to Q-tips) that you gently rub against the inside of the cheek for about 30 seconds. This collects enough DNA for testing without any blood or needles. The process works for everyone, including infants. Our kit includes clear instructions, and our customer service team is available if you need assistance.

There are no age restrictions for participating in a DNA twin test. Individuals of any age, including newborns, can take the test. However, for minors, consent from a legal guardian is required.