How to Read a DNA Test Result

By eHow Health Editor

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DNA testing is an integral piece of modern law and science. Through DNA testing criminals can be linked with crime scenes and ancestry can be traced through the generations. You do not need a PhD or MD to read the results of a DNA test. Follow these steps to learn how to read DNA test results.

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Instructions

Difficulty: Moderate

Things You’ll Need:

DNA test

Step1

Know the two main types of DNA testing. The first test, mtDNA, finds traits in both sexes inherited through the mother’s genes. The second test, Yline DNA, finds traits passed from father to son.

Step2

Learn the differences between the tests. If a mtDNA test is conducted on two people and the results match up, it can be concluded that they have a common maternal ancestor. A Yline test helps determine the distance between the common ancestor.

Step3

Know the limitations of the DNA test. DNA tests provide good information, but what is not certain is exactly how long ago the most recent common ancestor lived. In short, you may be related to someone and not know exactly how.

Step4

A strand of DNA is made up of four different types of miniscule building-blocks, also known as alleles. Scientists refer to them as A, T, G, and C. The sequence of these building blocks determine your species, height, weight and many other physical attributes.

Step5

In layman’s terms, the building blocks of a DNA test will be listed in their genetic order, such as ATTTGCCCTCG. To compare DNA, one can check the order of these letters or the corresponding reference ladders. If they are the same, then the DNA matches.

Step6

Learn what the DNA test results mean. If you read a Yline DNA test of two males, the more their DNA matches up, the better the chances are that they are related. The more matching alleles two individuals have, the closer you will be to finding their most recent common ancestor.

Tips & Warnings

DNA tests are not good at examining relationships across gender line. To determine the paternal relationship of a male to a female, samples from an aunt would be needed.
You can not assemble a full and accurate family tree based solely on DNA testing.