At a Glance
- Sample Required: Buccal swab (cheek swab)
- Fasting Rules: Not required
- Turnaround Time: 3–7 business days
- Base Cost: ₹24,000 (for 2 persons)
Written by: [Author Name] | Medically Reviewed by: Dr. [Reviewer Name], Medical Geneticist | Last Updated: [Date]
What Is a Sibling DNA Test?
A sibling DNA test analyzes specific genetic markers (Short Tandem Repeats, or STRs) to determine whether two individuals share one or both biological parents. This test is commonly used when a parent is unavailable for testing, for personal curiosity, or to resolve family questions.
The test can differentiate between:
- Full siblings (same mother and father)
- Half siblings (share one parent)
- Unrelated individuals
Note: This test is for peace of mind. For legal purposes (e.g., inheritance, custody), a legally admissible test with chain-of-custody is required.
How Does a Sibling DNA Test Work?
The laboratory examines 46 STR markers from each participant's DNA. The process involves:
- Sample Collection: Painless buccal swabs collected at home.
- DNA Extraction: DNA is isolated from the cheek cells.
- Marker Analysis: The 46 STR markers are amplified and compared.
- Statistical Calculation: A sibling index and probability of relationship are computed.
Full siblings typically share ~50% of their DNA, while half siblings share ~25%. The report provides a probability percentage indicating the likelihood of the tested relationship.
Accuracy and Limitations
Accuracy depends on the number of markers tested and whether additional family members (especially the mother) participate. With 46 markers and maternal DNA included, probabilities can exceed 99%.
💡 Key Takeaways
- •This article was written by Lookesh Sharma.
- •Last updated on September 9, 2026. Clinical information is reviewed periodically.
- •Always consult with a qualified healthcare provider before making medical decisions based on the information presented here.
Need Personalized Clinical Guidance?
The information in this article is intended for educational purposes and reflects current scientific understanding. To understand how these insights apply to your specific health profile or family history, speak with a certified genetic counselor at DNA Labs India.
Medical Disclaimer: The clinical insights provided here are intended for educational purposes and do not replace professional medical advice from a primary physician. DNA Labs India is an ISO 9001:2015 certified diagnostic laboratory. Always consult with a qualified healthcare provider regarding any medical concerns, diagnoses, or treatment decisions.
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