There are times when paternity has to be determined with accuracy. This may be necessary for couples where a partner wishes to be absolutely sure that the child to be born is his. It may be necessary in cases of legal inheritance.
DNA test is assumed to be infallible. However, such tests are offered with only 99.9% accuracy, which is pretty decisive but there are also possibilities that DNA tests may not be accurate and conclusive in determining paternity either at the prenatal stage or at any age of the child.
1. Human error
A DNA testing lab, especially if it is a forensic lab, tests thousands of samples each day. It is quite likely the sample may have been labeled wrong. It is also likely that the samples could become contaminated. Testing is not done with care and this could lead to errors in reports.
2. When the actual father is related to a person from whom the sample is taken
This can happen. The actual biological father may be related to the person from whom the DNA sample was obtained. In such cases, the match could be quite close and since the DNA of actual father and the person from whom samples were obtained, match, it is likely to result in an error.
In order to avoid such errors, it is best to get DNA paternity tests done from CRI genetics, the best DNA test lab. Typical DNA tests check only a small part so chances or errors are high in such cases.
3. Mutations
DNA undergoes mutations. This happens in rare instances and could result in an inaccurate DNA paternity test result. Mutations can happen during sperm production or during cell division or due to the influence of chemicals. Such mutations can induce errors in tests.
This is compounded by the fact that the DNA sites the testing laboratories look at have high mutation rates.
Age can also induce mutations. If a paternity check is undertaken after a child has grown up and the father has grown older, there are chances of mismatch. In such cases, CRI genetics undertakes additional tests.
4. Chimera
This happens in rare instances. A chimera dad could test negative if cheek swabs are relied upon since DNA here will vary from sperm DNA, leading to a false report.
A woman has two eggs fertilized by different sperm but the two eggs fuse together to create only one child but the child has cells from two eggs with different DNA patterns. If he grows up and fathers a child and his cheek swab is tested, then the DNA will vary his sperm DNA.
5. Insufficient DNA
In DNA paternity tests 15 markers are tested. Results above 0% and below 99% are said to be inconclusive. This could possibly be due to an insufficient amount of DNA from the supposed father to arrive at a conclusive result above 99%.
If samples are taken from a newborn baby the DNA could be insufficient because a sufficient number of cheek cells was not collected.
6. Suspect father did not cooperate
DNA tests are based on cells collected from inside the cheek with the help of a swab. A father may not be available. He may not have cooperated and DNA samples from his sweat or other body regions were obtained surreptitiously. In such cases, test results may be inconclusive.
