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California State University, Fullerton

Pollak Library

Genetic Genealogy: Testing

Understanding and using DNA for family history research.

Section Contents

Learn about autosomal DNA testing (all DNA, all ancestors), Y-DNA testing (patrilineal line), and mtDNA testing (matrilineal line).

Major Consumer Testing Companies

Family Tree DNA WebsiteFamily Tree DNA offers Y-chromosome (patrilineal/ direct-male line deep ancestry), mitochondrial (matrilineal/direct-female line, deep ancestry), and autosomal (all lines, recent ancestry) DNA tests.

  • Includes Ethnicity Reporting: Yes

  • Includes DNA Matches: Yes

  • Includes a Chromosome Browser (autosomal): Yes

  • Includes Health Reporting: No

  • Can Export Raw Data: Yes

  • Can Import Raw Data: Yes (from Ancestry and 23andMe, via an Autosomal Transfer for $15)

  • Can Attach an Online Tree: No (upload Gedcom only)

  • Testing Method: Cheek swab

23andMe offers autosomal (all lines, recent ancestry) DNA tests (with health reporting).

  • Includes Ethnicity Reporting: Yes

  • Includes DNA Matches: Yes

  • Includes a Chromosome Browser (autosomal): Yes

  • Includes Health Reporting: Yes

  • Can Export Raw Data: Yes

  • Can Import Raw Data: No

  • Can Attach an Online Tree: No

  • Testing Method: Cheek Swab

AncestryDNA

AncestryDNA offers autosomal (all lines, recent ancestry) DNA tests. 

  • Includes Ethnicity Reporting: Yes (plus Genetic Communities)

  • Includes DNA Matches: Yes

  • Includes a Chromosome Browser (autosomal): No

  • Includes Health Reporting: No

  • Can Export Raw Data: Yes

  • Can Import Raw Data: No

  • Can Attach an Online Tree: Yes

  • Testing Method: Spit in Tube

MyHeritage

MyHeritage offers autosomal (all lines, recent ancestry) DNA tests. 

  • Includes Ethnicity Reporting: Yes

  • Includes DNA Matches: Yes

  • Includes a Chromosome Browser (autosomal): No

  • Includes Health Reporting: No

  • Can Export Raw Data: N/A

  • Can Import Raw Data: Yes (transfer from AncestryDNA, 23andMe, and Family Tree DNA)

  • Can Attach an Online Tree: Yes

  • Testing Method: Cheek swab

The National Genographic Project

 

About the Project

Since its launch in 2005, National Geographic’s Genographic Project has used advanced DNA analysis and worked with indigenous communities to help answer fundamental questions about where humans originated and how we came to populate the Earth.

Tests Offered

The National Genographic Project offers Y-chromosome (patrilineal/direct-male line, deep ancestry) and mitochondrial (matrilineal/direct-female line, deep ancestry) DNA reports.

  • Includes Ethnicity Reporting: Yes

  • Includes DNA Matches: No

  • Includes a Chromosome Browser (autosomal): Not applicable

  • Includes Health Reporting: No

  • Can Export Raw Data: Yes (transfer free to Family Tree DNA)

  • Can Import Raw Data: No

  • Can Attach an Online Tree: No

  • Testing Method: Unknown

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Autosomal Testing: All DNA All Sides

About Autosomal DNA

"Autosomal DNA is a term used in genetic genealogy to describe DNA which is inherited from the autosomal chromosomes. An autosome is any of the numbered chromosomes, as opposed to the sex chromosomes. Humans have 22 pairs of autosomes and one pair of sex chromosomes (the X chromosome and the Y chromosome). Autosomes are numbered roughly in relation to their sizes. That is, Chromosome 1 has approximately 2,800 genes, while chromosome 22 has approximately 750 genes. There is no established abbreviation for autosomal DNA: atDNA (more common) and auDNA are used." - ISOGG Wiki

Who to Test?

"For autosomal DNA testing for genetic genealogy research one should always test the oldest generations first wherever possible - your parents, grandparents (if you are lucky), aunts and uncles. By testing yourself as well as your parents you will be able to determine which segments have been inherited from which parent, and you will also be able to rule out coincidental (Identical by state) matches. A two-parent/child trio also provides the best results for the purposes of phasing and chromosome mapping....[read more]" - ISOGG Wiki

Those doing autosomal DNA tests for unknown parentage cases (such as adoptees), different testing criteria applies.

Autosomal DNA Testing Providers

This is not an endorsement of any particular testing vendor or product.

Simple Mathematical Average of Sharing

A chart illustrating the different types of cousins, including genetic kinship marked within boxes in red which shows the actual genetic degree of relationship (gene share) with 'self' in percentage (%).

"Shows the average amount of autosomal DNA inherited by all close relations up to the third cousin level" (source: ISOGG Wiki). For more help and information on autosomal DNA statistics, visit the ISOGG Wiki.

Cousin Tree with Genetic Kinship

Creative Commons-licensed image from Wikimedia Commons.

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Y-DNATesting: Patrilineal Line

About Y-DNA

"A Y chromosome DNA test (Y-DNA test) is a genealogical DNA test which is used to explore a man's patrilineal or direct father's-line ancestry. The Y chromosome, like the patrilineal surname, passes down unchanged from father to son. A man's test results are compared to another man's results to determine the time frame in which the two individuals shared a most recent common ancestor or MRCA. If their test results are a perfect or nearly perfect match, they are related within a genealogical time frame. Each person can then look at the other's father-line information, typically the names of each patrilineal ancestor and his spouse, together with the dates and places of their marriage and of both spouses' births and deaths. The two matched persons may find a common ancestor or MRCA, as well as whatever information the other already has about their joint patriline or father's line prior to the MRCA. Y-DNA tests are typically co-ordinated in a surname DNA project. - ISOGG Wiki

Who to Test?

Only males can test. "Women who wish to determine their direct paternal DNA ancestry can ask their father, brother, paternal uncle, paternal grandfather, or a cousin who shares the same surname lineage (the same Y-DNA) to take a test for them." - ISOGG Wiki

Y-DNA Testing Providers

This is not an endorsement of any particular testing vendor or product.

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mtDNATesting

About mtDNA

"A mitochondrial DNA test (mtDNA test) traces a person's matrilineal or mother-line ancestry using the DNA in his or her mitochondria. mtDNA is passed down by the mother unchanged, to all children. If a perfect match is found to another person's mtDNA test results, one may find a common ancestor in the other relative's (matrilineal) "information table". However, because mtDNA mutations are very rare, the match will not necessarily be within a genealogical time frame." - ISOGG Wiki

Who to Test?

Males and females can be tested, but but only a direct matrilineal descendant can be tested. This is because while mother's pass their mtDNA on to both genders, only a female can pass it on to her descendants. There cannot be a male descendant sandwiched in between the person being tested and the most recent female in the matrilineal line .

For example, my brother can be tested for our mother's mtDNA, which includes her mother (our maternal grandmother) and her mother's mother (our matrilineal great grandmother). But he cannot be tested for our father's mother's mtDNA (our paternal grandmother), or either of our patrilineal (father's line) great grandmothers. To test for our father's mother's mtDNA, I would have to ask my father's sister (our aunt) or one of her children (our first cousins) to take the test.

mtDNA Testing Providers

This is not an endorsement of any particular testing vendor or product.

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