Sibling DNA Test

To determine a biological sibling or half-sibling relationship.

What is sibling DNA testing?

Do you want to know if you and your sibling share the same father? Or do you need to prove you have the same mother for immigration reasons? There are many reasons for doing a DNA sibling test, and DDC offers the latest technology and accurate testing to resolve questioned biological-sibling relationships. The report is posted to your secure online account 5-7 business days after all samples have been received. Every situation is unique: Contact our experts today for a free consultation.

The DDC Promise

Results in 5-7 Business Days

once all samples arrive at the lab.

PhD-Reviewed Results

Our in-house team ensures accuracy.

Team Support

We keep you informed every step of the way.

When set up as a legal case, results from a sibling DNA test can be used for inheritance benefits, proof of relationship for immigration, and more.

Reasons to get a Sibling DNA Test

The most common reason for taking a sibling DNA test is to confirm the truth about whether you and your sibling share the same father, mother, or both. Other reasons to take the test are:

  • To confirm the truth about a biological relationship
  • Medical history
  • Inheritance claims
  • Immigration cases
  • Insurance claims

Results are completely confidential, and your private genetic information is never shared with or sold to outside parties. See our privacy policy here.

Testing Options for Sibling DNA Testing

There are two main options for doing a sibling DNA test: legal or for personal knowledge.

Legal: Legal test results can be submitted to court as legal proof of a biological relationship. DDC helps you locate a DNA-sample collection provider near you. The professional collector then compiles all identification, completes paperwork for the test, and sends the package to DDC for testing.

Personal Knowledge: If you need the sibling-test results solely for peace of mind and not for legal reasons, you have the option to collect your DNA at home and send it to DDC for testing. Keep in mind results are not court-admissible.

TIP: If you think you may need results for court in the future, we suggest you do a legal test in the first place so you only have to test once.

To order a Sibling DNA Test, Call 0800 009 2969

More about sibling DNA tests

Q: Can sibling DNA test results be used for legal reasons?

A: Yes, sibling DNA test results can be used for legal reasons such as immigration, inheritance rights, and more, as long as you order a legal siblingship test with court-admissible results. A report for an at-home peace-of-mind test cannot be used for legal reasons.

Q: How does this test work if it is unknown whether the possible sibling is a half or full sibling?

A: If it is unknown whether the possible sibling is a full or a half, we first test to see if there is a biological relationship. If there is not, then testing is over. If a relationship is determined to exist, then we can do a full-sibling test at the request of the customer.

Q: How do I understand results for a sibling DNA test?

A: Understanding results for a sibling DNA test is a little complicated, since there can never be a straight “yes or no” answer in relationship testing. Calculations for relationships such as grandparent, avuncular (aunt/uncle), and siblings all involve statistics, and a probability of relationship is given as a percentage in the report:

  • 90% or higher: the relationship is supported by DNA testing
  • 9% – 89%: inconclusive result, and additional parties need to be tested
  • Below 9%: the relationship is not supported by DNA testing

If a probability of relationship (PRI) of 92% is given for a full-sibling test, the result could be understood as: “There is a 92% probability that the persons tested share a full sibling relationship.”

Q: My cousin could be my sibling. Can we do this test?

A: No, we cannot perform a sibling test if there might be a cousin relationship.