Join the The H600 Project
Introduction to Genetic Genealogy Testing
(that is, DNA Testing as a tool to help with your genealogical research)
Decide on which tests you can or should perform: Autosomal SNP, yDNA STR, yDNA SNP and/or mtDNA SNP
Autosomal SNP tests (FamilyFinder at FTDNA and simply included at 23andMe) can be used by ANYONE to possibly find ANY OTHER relative if you both share ANY ancestor within 6 or so generations. That is, if you have a common 1x to 5xGreat Grandparent. While we cannot support finding matches in our project directly, company testing sites provide support for matching those tested within that company. And GEDMatch is a third party site that allows you to upload your results and compare to others who have uploaded; possible finding more matches across company testing lines. Positive results are very likely if within 6 generations. After that, more distant relatives may still show some matching but the "norm" for fourth cousins is barely above the noise level of matching with the general population, for most people.
Results are reported as length's of common segments on a chromosome you have with someone else. This is determined by the detailed results of all the SNP markers tested. Individual SNP marker results are reported as changed or not; sometimes as deleted or added. Contiguous strings of common SNP marker results in a chromosome define a matched segment. The actual location of the end SNP's in such a segment on the chromosome are used to determine the "length". The more SNP's tested on every chromosome, the more accurate the results. The length's of segments, number of matching segments, and number of chromosomes with matching segments all contribute to helping determine how related you are.
Autosomal SNP tests are commonly used to determine the percentage makeup of your ancestry from different regions. This is done by identifying certain, more unique gene variations with populations or regions. As it looks across 44 chromosomes, there is more variety and mix of your recent background than solely with Y-DNA or mtDNA SNP. The accuracy of such regional background history is getting better every year but still the subject of much debate.
Note: Project experience tells us that the transfer of Autosomal SNP results from 23andMe to FTDNA is not worth the money. For best results, do autosomal testing directly at both companies. Our experience shows 23andMe's Haplogroup analysis on autosomal DNA to be more believable. But this changes often as each company incorporates more research.
yDNA STR testing can be used by males to test if they are related in their male-only ancestor line to others similarly tested. Females need to find a male sibling, cousin or the like. It works for upwards of 1,000 years (30 generations) and is not limited to the 6 or less generations of Autosomal SNP. For most of western Europe, the male-only line will follow the surname inheritence and hence the origination of Surname DNA projects like this one. This is the main test for this project. But it can only be done by those that are a believed male descendant all the way up the line.
yDNA STR testing is by far the largest component of FTDNA's user base. The 12 marker test is useful to see if you are in the ballpark with a surname project; for the lowest cost. A 37 marker test is really a minimum to verify you are in a surname family. More than 37 markers help determine branches in a family. You can start with a 12 marker test and upgrade later. Historically, there is no additional cost for testing incrementally; just additional time to reach your full results. Order a yDNA STR test in the Hoar / Hoare / Hore Surname DNA Project and become a member. Already tested at FTDNA? Simply join the Project. Were you yDNA STR tested at another company? Transfer your results to FTDNA to join this project or contact the admins. The yDNA STR test is somewhat unique to FTDNA but also offered by GeneBase.com and Oxford Assoc. See ISOGGs' yDNA STR Testing page for more info. Beside the matching inside the FTDNA company site / database, FTDNA also supports a free-site for members and non-members to register, upload and compare their results; see Ysearch.org.
Results are reported as a repeat number (or strand repeat length) for each marker. You should match all markers identically with near term cousins and be different by one in a few marker values for more distant cousins.
yDNA SNP and mtDNA SNP testing can be used to find your early human ancestry. Often termed Population Studies or Haplogroup / Phylo Tree understanding. Like for yDNA STR, yDNA SNP only tracks your male or paternal line. mtDNA SNP tracks your female-only or maternal ancestry as the Mitochondrial DNA is only passed down in the egg. The Y-Chromosome is inherited by males from their father. The mtDNA strand is inherited by everyone from their mother. SNP markers, by design, more rarely change and thus are commonly shared among many people. As such they are not as useful for nearer-term genealogy and surname work; except to help solidfy the STR results.
- yDNA SNP testing can help with the yDNA STR surname project by confirming your grouping. Those with very similar yDNA STR results should have identical Haplogroups as determined by their yDNA SNP results. STR results can sometimes predict, but not determine, the testers Haplogroup.
- mtDNA strands are very short (only about 16.000 base nucleotides) with very few SNP's. Thus it is very common to have the same mtDNA test results but no relation in genealogical time to each other.
- Because SNP's are often stable for thousands of years, those with common SNP test results may not be related in any genealogically determined time frame. Because SNP's do randomly change though, deep SNP studies in surname projects identify changes that have occurred within the last 500 years. Infrequent changes do not mean they cannot change in the near term. The once every 1,000 or 5,000 year change could have occurred in the last generation. Identifying these private SNP changes can sometimes help determine family lines in surname group just as STR changes can.
- Instead of individual SNP tests at FTDNA, project admins recommend testing with 23andMe or the National Geographic Genographic Project. With the latter, you can import your results into FTDNA as they have helped develop the project. But there are far fewer SNP's tested than with 23andMe. FTDNA only supports importing autosomal SNP results and not yDNA, xDNA nor mtDNA SNP results.
- Project leaders have spreadsheets and other support material to extract your ISOGG nomenclature SNP results from your downloaded 23andMe test data and map it into other versions of the ISOGG Y-DNA Haplogroup tree. Either into the 2010 tree FTDNA uses (so you can do apples-to-apples comparisons there) or into the latest 2014 tree available to understand the latest terminal SNP's used in this Surname DNA project. This avoids a need to do the one, many or all individual SNP marker tests with FTDNA. Report your SNP results to project admins and they will make notes attached to your account to help them in placing you into the right subgroup.
- Or simply check out Felix Immanuel's Y-STR.org page of many useeful tools and utilities he has built. Specifically a 23andMe converter and then a Google Chrome extension that turns your view of the online ISOGG Haplogroup tree into your personalized report. Many, many other useful tools there as well.
The Haplogroup tree for mtDNA is at PhyloTree but no tools to map into the latest one are available. FTDNA offers MitoSearch.org as a free, companion site for anyone to upload mtDNA results and compare to others.
Work with the project admins to map your results into the subgroups already identified or let them help take everything you have and figure out if there are any new avenues of genealogical research for you going forward. One of the project admins was stumped twice. Another admin helped them get past the name change around 1900 that was a complete surprise. And the DNA testing helped find the second name change at the 6th generation in 1800 by linking him to a 12th generation ancestor. Working forward from that ancestor drastically narrowed the search space to find the stumped 1800 link. So check out our pages and see if our collected genealogical research and DNA results might help you.
- Historically, forensics (criminal and paternal DNA testing) uses 13 loci of Autosomal STR. So Genealogical testing and criminal testing have no overlap in the results nor analysis. This should alleave some concerns when recruiting relatives.
- X-Chromosome testing is often lumped into Autosomal testing but some companies charge separately for it. Unlike the Y-Chromosome, the X-Chromosome may come from both parents (if a female, as you get one from each). X-Chromosome analysis is oft overlooked; mainly because tracking the source is more difficult. This is a similar issue to the 22 pairs of Autosome Chromosomes as well.
- In FTDNA SNP testing, you have to pay $745 to get only 10-20% of what you get for $100 from 23andMe. NGG Gene 2.0 is $200 to get a smaller subset of 23andMe Autosomal but more yDNA SNP's. The transfer of 23andMe results into FTDNA for $39 causes FTNDA to only include what they test in FamilyFinder -- they throw out all the somal (Y, X chromosome) and mtDNA SNP results.
- FTDNA has been saving the samples sent in since their beginning around 2000. 23andMe has only recently started saving samples and it is not yet clear what it means for them. One of our admins ordered an FTDNA test eleven years after the initial test / sample. The relative had long since passed on but he was able to get the benefit of the new testing technology. So something to consider when deciding vendors as well.
- FTDNA's reported database size is mostly based on yDNA STR only testers. Their SNP tester DB, for an apples to apples comparison and for FamilyFinder success rate, is believed to be 1/10 to 1/20th the size of 23andMe's. 23andMe testers use the product predominantly for health analysis and not genealogy. So although you may find matches there, actual responses to genealogic collaboration inquiries are sporadic. For best results, do autosomal testing directly at both companies. Our experience shows 23andMe's ethnic background analysis to be more believable.
We have been trying to collect an accurate table and comparison of the SNP testing capabilities of each company (and test version as it changes over time). Please help contribute if you have additional information. Here is what we have so far:
Number of SNP's Tested Strand 23andMe (v2 -2012) 23andMe (v3 2013) 23andMe (v4 2014-)6 NGG Gene 2.0 C3X3 FTDNA Affymetrix bef2012 FTDNA Illumina since2013 ALL ? 960,613 602,352 142,131 - ? 1 Auto+X 566.9057 956,388 596,869 130,109 - 725,310 2,7 Y ? 1,766 2,329 11,978 ? 3 25,000 3 Y in ISOGG5 ? (?) 333 (71) 425 (69) 1,837 (151) ? ? mtDNA ? 2,459 3,154 44 1,143 4 1,143 4 Cost $100 $100 $100 $200 ? 2,3,4 $745 2,3,4
4mtDNA Plus; they offer full sequencing to get the complete 16K base pairs,
5Number of Markers tested that are in ISOGG (in parenthesis, the ad hoc number of ISOGG SNP marker's showing a Positive Change for a few testers that were checked).
6 23andMe's newer test has reduced the overall number of Autosomal SNP markers but increased the Y and mtDNA test marker count.
7 Values from Felix Immanuel and his work on comparing Autosomal tests.
- SNP tests are, by design, looking for invarying single (or small sequence) base pair changes; often within genes themselves. SNP variations in a gene can be an indicator for health issues. STR tests, by design, look for more frequently changing repeat sequences in the inter-gene material that makes up a majority of your DNA. That is, outside the genes themselves. STR values generally change within a thousand years whereas SNP values change many thousands of years apart. This is by definition and design. So STR tests generally help prove you are related within a genealogical time frame. SNP tests can prove you are not related, if different, but say nothing when results are the same (except you historically, thousands of years ago, shared an ancestor).
- Some helpful charts on STR values are on Leo Little's page. Also, a useful backgrounder on DNA testing is on Kerchner's page. See our FAQ on Genetic Genealogy Terms in the Forums for some additional information. According to Felix, the BigY test from FTDNA includes all 480+ known STR regions on the Y Chromosome. So if you plan to eventually do BigY, limit your STR testing as it will be covered there.
If you still have questions, contact one of the Project Administrators listed at the bottom of the Surname Project's website.