What Happens If You Think Your DNA Test Result Is Wrong?
Can an Accurate DNA Test Be Wrong? Understanding the Possibilities
February 17, 2025
DNA testing is widely regarded as one of the most accurate and reliable methods for determining biological relationships. However, some individuals claim to have received wrong DNA test results, leading to confusion, emotional distress, and even legal disputes. But can a DNA test be wrong, and if so, why? Let’s explore the possible reasons for inaccurate results and what you can do if you suspect an error.
1. Can DNA Test Results Be Wrong?
Yes, while DNA tests are highly accurate—often boasting 99.9% precision—there are certain circumstances that may lead to incorrect or misleading results. These errors are rare but can happen due to:
✅ Human error in sample collection or handling
✅ Contaminated or degraded DNA samples
✅ Lab processing mistakes
✅ Low fetal DNA in prenatal paternity testing
✅ Testing the wrong person’s sample
✅ Rare genetic conditions (e.g., chimerism)
If you suspect a wrong DNA test result, it’s crucial to understand the potential causes before jumping to conclusions.
2. Possible Reasons for an Incorrect DNA Test Result
A. Sample Contamination or Handling Errors
One of the most common reasons for an incorrect DNA result is sample contamination. This can happen when:
🔴 The DNA sample gets mixed with another person’s DNA (e.g., touching the swab with unclean hands)
🔴 The test taker eats, drinks, smokes, or chews gum before sample collection
🔴 The sample is exposed to moisture, heat, or improper storage
B. Lab Processing Mistakes
Though rare, human errors in laboratory testing can happen. This may include:
🔴 Switched samples due to mislabeling
🔴 Incorrect analysis of genetic markers
🔴 Mistakes in data entry or result reporting
Reputable labs have strict quality control measures, but no process is 100% immune to errors.
C. Low Fetal DNA in Prenatal Paternity Testing
For non-invasive prenatal paternity tests (NIPP), accuracy depends on the amount of fetal DNA present in the mother’s bloodstream. If the test is done too early in pregnancy or if the fetal DNA is too low, the results may be inconclusive or incorrect.
Solution: If prenatal DNA test results seem questionable, consider retesting after a few more weeks of pregnancy to allow for higher fetal DNA concentration.
D. The Wrong Person’s Sample Was Tested
In some cases, the wrong sample may have been submitted. This could happen if:
🔴 The alleged father switches the sample intentionally
🔴 There is an accidental swap during collection
🔴 The test was done using a third-party sample (e.g., testing a relative instead of the actual father)
Solution: Always ensure proper supervision during sample collection, especially for legal DNA tests.
E. Rare Genetic Anomalies (Chimerism)
A rare condition called chimerism occurs when a person has two different sets of DNA. This happens when one twin absorbs the other in the womb. In such cases, a standard DNA test may show incorrect paternity results, as the DNA in saliva or blood may not match that of reproductive cells.
Solution: If a case of chimerism is suspected, advanced genetic testing using multiple DNA sources (e.g., blood, hair, skin, or sperm) may be necessary.
3. What to Do If You Suspect a Wrong DNA Test Result
If you receive a DNA test result that doesn’t seem right, follow these steps:
A. Verify the Sample Collection Process
Double-check that the samples were collected correctly and that no contamination occurred. If there’s a possibility of error, you may need to redo the test.
B. Contact the Testing Lab
Reach out to the DNA testing company and explain your concerns. Reputable labs will:
✅ Review their procedures
✅ Verify sample handling
✅ Offer a retest if an error is suspected
C. Request a Retest
If doubts persist, consider getting a second test from a different accredited lab. This will help confirm the results and eliminate any possibility of lab errors.
D. Choose a Legal DNA Test (if necessary)
For legal cases (e.g., child support, immigration, or custody disputes), ensure that the test follows a legal chain of custody, meaning samples are collected under supervision and properly documented.
E. How to Avoid Wrong DNA Results.
🔹 Follow proper sample collection procedures – Ensure clean, uncontaminated samples.
🔹 Confirm all test details – Double-check that the right individuals are being tested.
🔹 Request a retest if necessary – If results seem questionable, get a second opinion.
Final Thoughts: Can You Trust DNA Test Results?
While wrong DNA test results are rare, they can happen due to human error, contamination, low fetal DNA in prenatal testing, or rare genetic conditions. The best way to ensure accuracy is to follow all testing procedures correctly and work with a reputable, accredited DNA testing company.
If you’re in doubt, always verify with a second test to confirm the results and get the clarity you need.