How Accurate are DNA Paternity Tests

On behalf of Ronald H. Kauffman, P.A. posted in Paternity on Tuesday, November 12, 2013.

You hear a knock at the door late one night. Someone hands you papers naming you as the father of a child you’ve never met. The name of the mother is unfamiliar to you. Your first thought is “what if my wife finds out?” Your second thought is “I should take a DNA child custody test to see if I’m the father!” How accurate are these tests?

In cases where a man disputes he is the father of a child – and in some cases a court can prohibit you from even testing to find out – you may want to take a DNA paternity test.

In a DNA test, a Q-tip is scraped on the inside of your cheeks to collect buccal skin cells. The collection process is painless – at least as compared to a blood test – and takes only about 10 seconds per cheek.

The skin cells are used to extract your DNA. The test is looking for repetitive regions in your DNA. The test examines your DNA for different genetic markers, or alleles, which vary from person to person. For example, a test may show you have allele D7S820 with 15 repeats in your DNA. Someone else, on the other hand, may have only 10 repeats of D7S820.

Since the mother, father and child all have the same number of repeats, it means that there is a high probability that the child must be the offspring of both parents. DNA centers usually test 17 or more repeat areas, since relying on only one area would be too small a sample size.

But, what if the testing laboratory incorrectly analyzes a DNA sample? The Oklahoma Supreme Court considered exactly this problem in Berman v. Laboratory Corp. of America.

In Berman, the mother asked Oklahoma to determine the paternity of her child, and to collect child support from the father. An agency arranged for a lab to collect DNA for the test. The lab incorrectly reported that a man was not the child’s father.

However, after a different laboratory performed the DNA test, it found the same man was the father. The mother sued the first lab for the loss of past and future child support the father would have paid if the DNA test results were correct.

The Oklahoma Supreme Court decided that the lab owed a duty to the parents to use care in conducting accurate DNA testing for child support.

The importance of reliable and accurate DNA results cannot be overstated. You should always have professional advice instead of just trusting a piece of paper assuring you “probability of paternity 99.99%”.