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Hiring a DNA Testing Company

Revision as of 11:42, 14 June 2022 by TannerBlairTolman (talk | contribs)

DNA testing has become an accepted tool for identifying ancestors and for verifying genealogical leads. It is also used frequently to learn about our deep ancestry. Testing your family DNA sometimes results in finding cousins who may have more genealogical information than you.

What is DNA?

To better understand DNA testing it is helpful to have a basic understanding of how DNA is inherited. The University of Utah's Genetic Science Learning Center's page Basic Genetics is an excellent resource.

DNA is based on the 46 chromosomes that every human being has (with few exceptions). The sex-determining chromosomes are X from the mother and either X or Y from the father. If X from the father, the child is female (XX) and if Y from the father the child is male (XY). The Y-chromosome can be traced from father to son to son and so on.

In addition, each human being carries a genetic molecule in their cells called the mitochondrial DNA (mtDNA). This genetic component is found in organelles called mitochondria, which produce energy for the hosting cell. mtDNA is inherited exclusively along the mother side. Both males and females carry mtDNA, but only women will pass their mtDNA to their children. Both mtDNA and Y DNA can go back hundreds of years, because of their slow mutation rate. They can be used to help verify or find direct maternal or paternal lines.

Autosomal DNA is the DNA found on the rest of your 44 chromosomes. It is a mix of all your ancestor lines not just your direct maternal or paternal line. Autosomal usually shows about 6-7 generations back.

DNA Double Helix.png

Getting Started with DNA Testing

CeCe Moore's "DNA Testing for Genealogy - Getting Started" series is a great place for beginners. It is also great for helping to decide which type of DNA test to do. Read her posts at the Geni blog:

Y-DNA Testing

Information stored in the Y chromosome (Ycs) passes virtually unchanged from father-to-son for centuries. Analysis of this genetic information, found in living people, can help you determine whether you share a common paternal ancestor with another person alive today. Based on the number of genetic markers shared on the Ycs with another person, you can also estimate how many generations in the past your common paternal ancestor lived. This is called Time to the Most Recent Common Ancestor (TMRCA) and it is based on a mutation rate calculated on many thousands of father/son pairs. Ycs testing can help in verifying a common paternal ancestor, or learn about the origin of a particular surname. Additionally, each Ycs can be predicted into a specific branch of the large Ycs tree based on the set of Short Tandem Repeats (STRs) tested by many companies and using an online predictor, or it can be accurately assigned to one of these branches through the test of Single Nucleotide Polymorphisms (SNPs) (see the Ycs ISOGG tree).

Note: Only males carry the Ycs, but a woman can have a male relative tested in her stead to obtain such information.

MTDNA Testing

Mitochondrial DNA (mtDNA) is a small circular genetic molecule found outside the nucleus in organelles called mitochondria. It is inherited exclusively from our mothers and it follows an unbroken maternal line. MtDNA is helpful in verifying the existence of a common maternal ancestor or to study the ancient origins of our maternal line. MtDNA lineages can be grouped together in a large mtDNA tree. Each branch of this tree may have a specific geographic distribution that might help someone locate the country or region of origin of their maternal line.

MtDNA testing can be done for a small section of the genome called the control region (which usually include the segments HVR1, 2 and/or 3), or for the full molecule (16569 bases). Family Tree DNA is currently the only commercial laboratory offering the complete mtDNA sequence to its customers.

Note: Although mtDNA is inherited exclusively along the maternal side, both males and females carry it. Only females will pass it on to their children. ISOGG has a useful diagram which shows the path of mtDNA transmission.

Autosomal DNA Testing

Autosomal DNA is the DNA found in the 22 pairs of nuclear chromosomes. They are shuffled at each generation and only half of it is passed to our offspring. It does not follow a clear and straight path of inheritance as the Ycs and mtDNA described above. However, current testing provides a survey of one million or more sites on a person nuclear genome. This information is helpful in identifying recent cousins within the last five generations, or the ethnic origins of our family tree. Companies like 23andMe, Family Tree DNA, and Ancestry all offer autosomal testing for genealogical purposes. The Genographic Project recently launched an autosomal test that offers insights into our deep ancestry. These tests offer a lot of information about our DNA and they may be difficult to understand. Each company offering such tests has numerous tutorials and aids on their website to assist with the interpretation of such results. 

ISOGG's "Autosomal DNA testing comparison chart" provides useful information for selecting a company to process your atDNA.

DNA Testing Companies

Some major commercial DNA testing companies are listed below in alphabetical order. Please visit their websites to learn more about their services:

23andme

23andme was founded in April 2006 and is based in Sunnyvale, California. They sell autosomal DNA kits with two options. Ancestry + Traits (base price $99) and Health + Ancestry (base price $149). The latter includes everything in the former plus health reports. They also sell memberships for $29 which grant access to additional features. The main benefit of the membership for genealogists is that it allows you to see your top 5000 matches whereas without it, you can only see your top 1500.

For genealogists, the biggest strength of 23andme is their chromosome browser. Unlike the chromosome browswers provided by FtDNA and MyHeritage, 23andme will show you if you share X-DNA with a match. This can help you more easily determine how you are related to a genetic match by eliminating several lines. Also unlike FtDNA and MyHeritage, 23andme's chromosome browswer allows you to compare any two of your matches against each other whereas both FtDNA and MyHeritage only allows you to compare them against yourself. This means you can more easily determine if two matches are closely related such as mother-son, siblings, or second cousins. The difference can be important as you try to use DNA to prove your descent from a common ancestor.

Another advantage to 23andme is they predict your paternal and maternal haplogroups meaning they predict what branches of the human family your Y-DNA and mtDNA belong in. They do not provide match lists for these parts of your DNA but you can check to see if your haplogroups match another test taker when trying to find the common ancestor.

23andme has a unique tree feature. Instead of uploading your tree, 23andme compares your DNA against everyone else in the database and tries to construct a genetic tree for you and predicts where your top matches belong in your tree. The initial tree is usually not perfect, but is fairly accurate. This generated tree can be adjusted meaning more people can be added and people can be moved from there predicted locations to their true ones. The tree is more of a tool to show how you are related to your other matches than a traditional pedigree.

The biggest disadvantage to 23andme is their tree feature only lets you add up to 300 relatives and only 5 other people can have permission to view it at a time. They do have a place where you can provide a link to your tree somewhere else like Ancestry or MyHeritage, but most test takers have not included one or they have linked to their FamilySearch tree, not realizing only they can see it because they are living and therefore marked as private in FamilyTree.

To summarize, 23andme is a great company and for an advanced genetic genealogist who knows how to use a chromosome browser and figure out who people are even when they don't have a pedigree and don't respond to emails. A test taker without those skills and who lacks the time and effort to obtain them will likely make little headway trying to solve brick wall ancestors. Those who are looking for closer relatives such adoptees or those who have given children up for adoption, should definitely test with 23andme just in case the one close relative you are looking for has already tested in their database. Maybe your biological mother is in 23andme but not any other company.

Ancestry

Ancestry was founded in 1996 and has been selling DNA tests since 2012. They are based in Lehi, Utah. They sell Ancestry kits for $99 and Ancestry plus traits for $109. Often you can also add a three month membership to Ancestry's record database for $1 when you purchase a kit through them.

The biggest advantage to AncestryDNA is their database. As of November 2018, they have sold over 18 million DNA kits. The sheer size of their database makes it more likely that you will find a genetic relative of interest to your problem. The other major advantage to Ancestry is the ability to link your DNA and pedigree together. You can upload your tree, link your DNA to yourself in the tree and then Ancestry will start comparing your tree against all your genetic relatives who also have linked their trees to their DNA. Not everyone has done this and many users have both DNA and a tree, but have not linked the two.

Another major strength is their Thrulines feature. After Ancestry has compared your tree and tried to find as many genetic connections as possible, Ancestry will allow you to see all of these possible connections using Thrulines. Thrulines allows you to click on an Ancestor, and then it shows you all the other matches it thinks descends from that Ancestor and their relationships. It can even use their massive database of online trees to fill in some of the gaps when a match of interest only has a partial tree. One important thing to know about Thrulines is that it does not "go through the DNA" despite what many people seem to think. The formulas is simple, if two people share DNA their trees are sought for a common ancestor, but the DNA still needs to be analyzed to make sure that Thrulines found the right common ancestor. For example, Tanner Tolman has a match that according to the paper trail should be related on his grandmother's side. However, there was a non-paternal event and this particular individual is actually genetically related on his grandfather's side. This is obvious when looking at the shared matches, but Thrulines incorrectly assumes the relationship is on grandmother's side. In other words, Thrulines is great, but do not accept it without verifying the conclusions.

One more strength of Ancestry worth mentioning is their dot system. You can create custom groups, assign each group a color and then place colored dots on each match you believe belongs in that group. You can use these dots with the Leeds method to help identify matches that may be related to your brick wall ancestor.

The biggest disadvantage to Ancestry is their strict privacy rules. They do not have a chromosome browser, they do not have an auto cluster tool, and although they let you see people who share DNA with both you and another genetic match, they do not let you see how closely those shared matches are related to the other person. This can make things difficult when trying to construct a hypothetical tree or when people do not respond to emails asking for more information (which happens frequently). Many people in Ancestry's large database, bought the test, looked at their ethnicity results once, and then never logged in again. Also, to get the full value out of your AncestryDNA test, you will need a membership to Ancestry. Otherwise, you will not be allowed to look at the trees uploaded by your matches.

In summary, Ancestry has strict privacy rules which can be irritating for advanced genealogists and those interested in chromosome mapping, Thrulines is not perfect, and many matches do not respond to emails which is especially hard for beginning genealogists. However, the size of their database really does make up for a lot. Many genealogists still consider Ancestry to be the best company for genetic research, especially if those researchers are working on brick wall Ancestors who lived in the United States. Those who are looking for closer relatives such adoptees or those who have given children up for adoption, should definitely test with Ancestry just in case the one close relative you are looking for has already tested in their database. Maybe your biological mother is in Ancestry but not any other company.

23 and Me

  • Autosomal (with paternal and maternal Haplogroup assignment)
  • Ability to connect with people who are DNA matches
  • Offers health test
  • Chromosome browser feature
  • Physical traits feature

AncestryDNA

  • Autosomal
  • Ability to connect with people who are DNA matches
  • Physical traits feature

DNA Consulting

  • STR markers (form of autosomal)
  • Y-DNA (25 markers)
  • mtDNA

FamilyTree DNA

  • Autosomal
  • mtDNA (with maternal Haplogroup)
  • Y-DNA (37 markers through 111 markers with paternal Haplogroup)
  • Ability to connect with people who are DNA matches
  • Chromosome browser feature

Living DNA

  • Autosomal (with paternal and maternal Haplogroups)
  • no tree feature at this time

MyHeritage

  • Autosomal
  • Ability to connect with people who are DNA matches
  • Chromosome browser feature

Public DNA Databases

Defunct Public DNA Databases

Genetic Genealogy Standards

In 2015, a group of expert DNA genealogists developed a set of standards to help people accurately interpret their DNA test results. The standards are available on the group's website The Genetic Genealogy Standards.

Result Analysis

Organizations, such as The Genetic Genealogist, The Genetic Genealogy Consultant, and Your Genetic Genealogist provide services to help you interpret your DNA results and get the most out of what they can tell you about your roots.

DNA Projects

Thousands of DNA Projects, usually focused on a particular surname, location, or ethnicity, are active around the world. A listing of geographical projects can be found in the ISOGG Wiki.

Examples of individual projects include:

FamilyTree DNA has several projects, including the following:

A list of FamilyTree DNA projects can be found on their FamilyTreeDNA Group Projects page.

Adoption-Specific Projects

These projects have created with the specific purpose of helping adoptees find their biological families.

Websites

 Wikipedia has more about this subject: Genetic genealogy

Disclaimer

Neither The Church of Jesus Christ of Latter-day Saints nor FamilySearch International is associated in any way with any DNA study. As a non-profit organization, FamilySearch cannot recommend a specific DNA-testing company to you.

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