About Postnatal Sibling DNA Testing

What is Postnatal Sibling Testing?

Postnatal sibling DNA testing is a genetic test used to determine whether two or more individuals are biologically related as siblings. It is commonly performed in cases where a sibling relationship is in doubt or when resolving legal or familial matters. This type of test can confirm a biological sibling connection even if the parents are unknown or unavailable. However, having access to the DNA data of a shared parent (father or mother) increases the accuracy of the result. Without either parent’s DNA, the test can only indicate a high likelihood of a sibling relationship, not absolute confirmation. Notably, tests between male siblings are generally easier to interpret.

Purposes of Sibling Testing

Sibling DNA tests serve a variety of purposes:

1. Inheritance issues: Confirming a sibling relationship can help resolve questions about inheritance rights and legal matters.
2. Family verification: For those who wish to scientifically validate a family relationship, sibling testing is a reliable method.
3. In absence of parents: Even if a parent is deceased, sibling testing can still confirm genetic relationships among siblings.

How the Test Works

Sibling testing typically involves the analysis of short tandem repeats (STRs) in DNA. Since siblings inherit their DNA from their parents, they share portions of their genetic material. The degree of this shared genetic material can be analyzed to determine the likelihood of a sibling relationship.

• Full-sibling testing: If both parents are shared, the siblings are expected to have a higher percentage of matching DNA markers.
• Half-sibling testing: If only one parent is shared, the percentage of matching markers will be lower but still significantly present.

Testing Procedure

1. Sample Collection: DNA samples are collected from the individuals being tested, typically by swabbing the inside of the mouth with a cotton swab. This is a painless and non-invasive process.
2. DNA Analysis: The collected DNA is analyzed in a specialized laboratory. STR regions of the DNA are examined to evaluate the genetic similarity between the individuals.
3. Result Interpretation: Based on the degree of DNA match, a determination is made as to whether the individuals are full siblings, half siblings, or unrelated. Full siblings typically show a very high level of genetic similarity, while half siblings show a moderate degree of matching.

Accuracy of Sibling Testing

Sibling DNA testing is slightly more complex than paternity testing because siblings share less genetic information compared to a parent-child pair. However, with high-precision STR (short tandem repeat) analysis, it is possible to determine with over 99% probability whether individuals are full siblings or half siblings.

Privacy and Security

Strict privacy protections are upheld throughout the sibling testing process. DNA samples and test results are never disclosed to third parties and are used securely for legal procedures or personal purposes only.

Common Situations Where Sibling Testing Is Used

• Inheritance or legal matters: Sibling testing can be crucial in proving biological relationships needed to resolve inheritance rights or other legal issues.
• Family reassurance: Scientifically confirming a sibling relationship can help ease doubts within families and provide peace of mind.
• In the absence of parents: When parents are deceased or unavailable to verify relationships, sibling DNA testing offers a way to confirm genetic ties between siblings.

Private Postnatal Sibling DNA Testing

In private postnatal sibling testing, only a buccal (cheek) swab is required. A sample collection kit will be sent to your home. For private (non-legal) testing, simply collect the DNA sample using the cheek swab, return the sample to us, and you will receive the results via email in approximately 5.5 business days.

Testing Procedure (Private Testing)

STEP

Contact Hiro Clinic by phone or purchase the test kit from GenerioStore.

STEP

Visit Hiro Clinic, where a DNA sample will be collected from the inside of your cheek.

STEP

Send the collected sample along with the consent form to the Tokyo Hygiene Laboratory.

STEP

The test results will be sent to you by email.

Legal Postnatal Sibling DNA Testing

Legal sibling DNA testing is available at Hiro Clinic for cases where official documentation is required. This type of testing is especially useful when submitting evidence to a court or other legal authority. We generally recommend legal testing for its higher credibility and formal recognition.

Testing Procedure (Legal Testing)

STEP

Contact Hiro Clinic by phone or purchase the test kit through GenerioStore.

STEP

Visit Hiro Clinic for DNA sample collection via buccal swab.
Before the sample is collected, identity verification and video recording of the collection process will be conducted.

STEP

Send the collected sample and signed consent form to the Tokyo Hygiene Laboratory.

STEP

Test results will be sent via email.
For legal testing only, a paper certificate signed by a doctor will also be issued and sent afterward.

Postnatal Half-Sibling DNA Testing

This test is used to determine whether two individuals share one biological parent. By collecting DNA samples via buccal (cheek) swabs from the suspected half-siblings and their common parent, it is possible to confirm a half-sibling relationship. Testing can be performed with DNA samples from all three individuals: the two siblings and their shared parent.

Find the Right Sibling DNA Test Kit for You

Pricing Information

Postnatal Full Sibling DNA Testing

Postnatal Half-Sibling DNA Testing

If you wish to undergo legal testing, DNA sample collection will be conducted at Hiro Clinic under the supervision of a certified testing physician. Please make sure to select the legal testing option when purchasing through GenerioStore.