At PRO-DNA Diagnostic we have always been passionate about twins and twin zygosity testing.

The reason is very simple, I am a twin and I know first hand the emotional implications of having a brother that has exactly the same genetic code as yourself. As you know not all twins are identical. Often fraternal twins look alike and they may have been brought up as identical twins even if they are not. The reverse is also true. Only DNA analysis allows us to definitely confirm if twins are identical since they will have the same genetic profile. It is therefore possible to determine with certainty whether twins are identical or fraternal.

Most twins will undergo a twin zygosity test to dissipate any doubts about the fact that they really are identical or fraternal. Sometimes, the results of the test are not always as expected. We have confirmed the mono-zygosity of twins who had been told that they were not identical. Zygosity testing is mainly done for pure personal motivation. However, it is also possible that this information could be useful for medical purposes in the unlikely event that one of the twins is affected by cancer or renal insufficiency. An identical twin can serve as the perfect donor for bone marrow transplantation or for living kidney donation since no rejection will occur. Fortunately , the results of a zygosity test will primarily allow twins to know the truth about their own origin and identity!


Lambert Busque MD
Medical and Scientific Director
PRO-DNA Diagnostic



How to order
You can order on-line by clicking the order button on our secure web site and filling out the request form. For the security of our customers, credit card information is automatically transferred to the financial institution; laboratory personnel do not have access to credit card information.

You can order by fax at (450) 663-4428 by filling out the following form. Please identify the required test and desired options, delivery adresss for sampling kit, credit card information (VISA or MASTERCARD, card number, expiry date, card holder's name), your phone number and e-mail.

You can order by phone at 1-888-988-1888 (Canada & USA) or (450) 663-6724 ext. 247.

Sampling and Specifications
The DNA test is performed on a buccal swab sample. This simple, painless type of sampling procedure yields results that are as reliable as blood sampling results. Moreover, it can be performed as easily on a newborn or child as on an adult.

For customers wishing to undergo the Twin zygosity test for legal purposes, our laboratory takes charge of coordinating appointments with one of our sampling centres in your community. Customers are asked to present several pieces of photo ID at their appointments.

For customers wishing to undergo the Twin zygosity test — at-home sampling, upon receipt of payment, our laboratory will send you a sampling kit together with instructions and a return envelope. The package will also include consent forms to be completed and signed by the test participants and, if applicable, by the legal guardian of any participants who are minors. Before performing the test, our laboratory will verify each person's consent by telephone.

The results are released within 10 working days following the laboratory's receipt of the samples.

Payment Procedures
Our laboratory accepts Visa and MasterCard credit cards, as well as debit cards, certified cheques, postal money orders and cash.

In certain situations, the costs of the twin zygosity tests may be borne by the Legal Aid office in your community. You may contact our laboratory to find out the address of your local Legal Aid office.