Types of DNA
Autosomal DNA, Y-DNA, X-DNA or mtDNA
There are many different types of DNA, so how do you get started working out which type of test to take? Here is a brief guide to the different types of DNA and tests available and suggestions on when each can be useful.
There are four types of DNA that can help with your family history research
There are four types of DNA. Most tests look at autosomal DNA and some of those include X-DNA too. There is also Y-DNA and mtDNA. Here's how they differ. If you are interested in autosomal DNA testing but not sure which company to use see my guide on Maximising Your Success with Autosomal DNA.
Autosomal DNA
By far the most common test is an autosomal DNA test. This is the type of test you buy at Ancestry, My Heritage, 23andMe and Living DNA and is one of the tests available from Family Tree DNA. An autosomal test is often called a ‘close cousin’ test because it can be used to connect with cousins who share an ancestor, typically within 5-7 generations. We inherit autosomal DNA from all lines of our family within that time period. Anyone can take an autosomal DNA test.
Y-DNA
Y-DNA is carried only by males and is transmitted through the male to male to male line, largely unchanged for many generations. It can be used to find connections to ancestors far further back in time than autosomal DNA but only through one single line of your family tree. It is often used in surname studies and is also used for investigating ancient origins. Only males have Y-DNA and can take a Y-DNA test.
Mitochondrial DNA (mtDNA)
mtDNA is carried by males and females but only females pass it on to the next generation. mtDNA passes through the female to female to female line, unchanged for many generations. mtDNA is useful for looking at ancient origins and identifying remains. Anyone can take a mtDNA test.
X-DNA
X-DNA is not a separate test in its own right but some companies report X-DNA matches with your autosomal matches. Both males and females have X-DNA. It has a complex inheritance pattern and is most often used in combination with autosomal DNA to assign matches to a particular part of your family tree.
What is DNA?
DNA is found in almost every cell in the human body. Most of our DNA: the autosomal DNA, X-DNA and Y-DNA is found in the cell nucleus. The fourth type of DNA, mitochondrial DNA, is found in the mitochondria. The ways in which the different types of DNA are passed from parent to child varies, depending on the type of DNA. Different tests are therefore more useful for different testing aims. For example, Y-DNA tests can be very useful for surname projects looking to find out if all bearers of a surname are related.
Autosomal DNA can be fantastic for problems solving in recent generations of family trees. I can guide you through all the jargon and help you make the most of your DNA test results.
