Special Services - DNA Sibship Test


Analysis of the DNA of two separate individuals can provide information as to whether they are full siblings, half siblings, or not related. However, unlike paternity testing which provides very conclusive results: 100% for non-paternity and greater than 99.9% for paternity inclusion, the answers provided by sibship testing are not always so conclusive. The results of the sibling test are for private knowledge only. If you require the sibling test for legal use, you must contact Genex at 1-844-331-0109 to arrange an appointment for specimen collection at one of our facilities so that the collection procedure is witnessed. Please fully understand the benefits and limitations of the sibship test before ordering.

About Sibship Testing

When the issue of sibship is in question, the recommended method to determine whether individuals are true biological siblings is to test their parents. DNA paternity and sibship testing will provide conclusive results. However, in situations where the alleged parents are unavailable for testing, a DNA sibship test can be performed to analyze the relationship of biological siblings.

Unlike a DNA paternity test which will always provide a conclusive result, sibship tests are different. When a sibship test is conducted, the DNA laboratory will determine the genetic profile of the alleged siblings. Based on the type of genetic material inherited by each sibling, a sibship index is determined. If the sibship index is less than 1.00, this indicates non-relatedness. If the sibship index is greater than 1.00, this indicates that the two tested individuals are more likely to be true biological siblings. The higher the value of the sibship index, the greater the likelihood that the two individuals are true biological siblings. To analyze the possibility that the siblings share only one common parent versus two common parents (mother and father), a half sibship index is obtained. The ratio of the half sibship index versus the full sibship index would provide you with an idea of whether the two individuals are more likely to share only one common parent (e.g. mother only) or two common parents (mother and alleged father).

Although the sibship test will not provide you with a conclusive answer, it may be able to provide you with an indication of whether you are more likely to be or not to be the true biological sibling of the other tested individual.

Quick Facts

Test Type DNA Sibship Test
Individuals Involved Two or more potential siblings
Description To determine whether two or more individuals are biological siblings. To determine whether siblings are full siblings (2 common parents), or half siblings (1 common parent).
Fee for Private Home Test [?] $180 US for testing two individuals
Fee for Court-Admissible Home Test [?] $255 US for testing two individuals
Fee for Legal Test [?] $355 US for testing two individuals, plus specimen collection fee
Specimen Buccal swab (blood is also acceptable but not recommended)
Turnaround Time Regular: 3 to 5 business days, Express: 2 - 3 business days
Method of Reporting Mail, Email, or Telephone
Ordering This test can be ordered by phone, fax, mail, or online:
  • By phone: 1-844-331-0109
  • By Fax or mail: download a printable Order Form
  • Order online: order online 24 hours a day


Step 1 - Order the test. Order laboratory testing by phone at 1-844-331-0109 or by mail, or order the private DNA collection kit online.

Step 2 - Collect and submit the samples to the laboratory. Kits are delivered to your door within 24 hours by courier or within 5 working days by mail. Each Sibship test kit comes complete with all of the collection materials and instructions for you to take the test in the privacy of your own home. All Sibship testing kits employ the buccal swab technique, allowing you to perform the collection within minutes with no fuss, no pain. Submit the DNA specimen directly to the laboratory after collection.

Step 3 - Wait for results. Sibship test results are available within 3 to 5 working days (or as soon as 2 days for the express test) and can be obtained as soon as testing is completed using your secure order number and password online or by phone. Formal results documents are delivered to you by mail and / or E-mail. You may also call our laboratory to discuss your results over the telephone. To ensure the privacy and confidentiality of your case, we will confirm your password and file number before we discuss results over the telephone (the password and file numbers are provided to you when you order the test).

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