DNA Testing Tips for Beginners

I recently took an AncestryDNA test because of my interest in genealogical research. I read up on DNA testing before taking the test yet still missed crucial tips and notes on understanding results. I am writing this blog post so that anyone interested in a test can make the most out of it from the get-go. (Please note: I do not have an affiliations with any of the companies I mention or suggest. Comments with further advice are welcome.)

After ordering the test, I received my kit within a couple of days. Further on that, my results arrived after about 8 weeks. If you have trouble spitting into the tube, I advise you to softly bite the inside of your cheeks or tongue as that will produce more saliva.

My Ethnicity Results

On paper, I am 75% English, 22% Scottish and 3% Irish. Because of this I was expecting a high amount of Great Britain, some Scandinavian and some Irish. However, the ethnicities I got and the proportions were entirely different to this. (Which, for me, made the money spent so much more worthwhile!)

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Upon receiving the ethnicity results, I began trying to understand why I came up with the unexpected ethnicities that I was marked as. I found this article (http://www.dailymail.co.uk/sciencetech/article-3711040/How-British-Genetic-study-reveals-Yorkshire-Anglo-Saxon-UK-East-Midlands-Scandinavian.html) to be the most helpful, explaining my Europe West, Italy/ Greece, Iberian Peninsula, and Finland/ Northwest Russia DNA. Furthermore, I read elsewhere that 1% of Scottish descendants have Berber (North African) ancestry (http://www.bbc.com/news/uk-scotland-17740638).

 

The Average Brit:

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Reading the Results

 

Cousin Matches

Top tips I have found online (http://blog.kittycooper.com/2016/08/michelles-ancestrydna-tips/):

  1. Write the relationship between you and your match in the notes. This saves you from having to click away from the home page to see the match, and in case your cousin removes or changes their tree.
  2. Put a star next to each of your confirmed ancestors. This is for the purpose of knowing whether an NPE (Non-Paternal Event) has occurred or not.

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3. For each cousin match there is a little ‘i’ next to the confidence bar. Hovering your mouse over that shows how many ‘centimorgans’ of DNA you share. Divide this number by 68 and that is how much % DNA you share.

 

Beyond AncestryDNA

gedmatch.com

  • Uploading your raw data to gedmatch can increase your chances of finding cousins who have tested with other companies.
  • It is also useful for chromosome mapping (attributing your inherited chromosomes to particular ancestors based on your cousin matches).
  • You can run your data through various ethnicity simulators to see how the results differ to what Ancestry has ascribed you (however, these are apparently unreliable in comparison).
  • Gedmatch can guess your eye colour (and it’s pretty accurate)
  • Gedmatch can guess whether your parents are related or not

Genetic health report

  • I used Promethease for $5. I believe it was accurate as it told me I had genes for things that my grandparents and parents have had. Promethease was sometimes confusing and messy as you will have one gene for something (i.e. cancer) and other genes that contradict that gene, yet Promethease doesn’t summarise your actual chances of having it vs. not having it.
  • Livewello is apparently good and it costs about $20, however I have not used it. Some people commented issues regarding subscription to see full results.

y-dna & mitochondria

  • Again, not something I have used yet though I plan to, Family Tree DNA is apparently the best website for testing y-DNA haplo groups and mitochondria. These are your direct paternal and maternal lines and the results go back hundreds of thousands of years. https://www.familytreedna.com

Groups

 

Glossary

Admixture: Ancestry from more than one recent population group. Many people today have ancestry from more than one population and/or location.

Autosomal DNA: Autosomal DNA is DNA from one of our chromosomes located in the cell nucleus. It generally excludes the sex chromosomes. Humans have 22 pairs of autosomal chromosomes and a pair of sex chromosomes.

CentiMorgan (cM): A measurement of how likely a segment of DNA is to recombine from one generation to the next. A single centiMorgan is considered equivalent to a 1% (1/100) chance that a segment of DNA will crossover or recombine within one generation. For humans, one million base pairs (bp) average about one centiMorgan. However, the rate of recombination is highly variable.

Centromere: One of the parts of each chromosome. It is a dense area that joins together the two chromatids (arms) of each chromosome.

Chromosome: A chromosome is a structure found in the nucleus of a cell that contains genetic material. Humans have 23 pairs of chromosomes: 22 pairs of autosomes and one pair of sex chromosomes.

DNA (deoxyribonucleic acid): The genetic code that makes each of us a unique individual. Humans inherit about one half of their genetic code from each of their parents. Our genetic code then holds the story of our heritage that has been passed down through the generations.

Gene: A region of DNA which codes for a protein or part of a protein.

Genome: The entire complement of an organism’s genetic material. This may refer to the DNA of a gamete, organelles (mitochondria and chloroplasts), organism, or species.The human nuclear genome is composed of 46 chromosomes (23 pairs). They contain a total of 3 billion base pairs.The human mitochondrial genome is composed of a single circular DNA sequence that contains 16569 base pairs.

Haplogroup: A major branch on either the maternal or paternal tree of humankind. Haplogroups are associated with early human migrations. Today these can associated with a geographic region or regions.

Heterozygous: two genetic code values (alleles) at a point in the genetic code are different.

Homozygous: two genetic code values (alleles) at a point in the genetic code are identical.

IBC (Identical by chance): A false cousin match

IBD (Identical by descent): A segment of inherited by two people through a common ancestor without recombination.

IBS (Identical by state): Not identical by descent.

Mitochondria: Specialized subunits (organelle) within cells. In humans, mitochondria are responsible for cell respiration and for producing energy. They evolve into their current state from separate organisms that form a mutually beneficial (symbiotic) relationship with the larger cell. Because they were once independent, they have their own mitochondrial DNA (mtDNA) genome. This genome is passed from human mother to child.

Mitochondrial Eve: The common matrilineal ancestor of all living humans.

Mutation: A heritable change that occurs in genetic material. It may lead to a different number of repeats of a certain sequence or a change in one of the bases in a sequence.

NPE (Non-Paternal Event): An event which has caused a break in the link between the surname and the Y-chromosome resulting in a son using a different surname from that of his biological father (eg, illegitmacy, adoption, maternal infidelity).

Polymorphism: A change in genetic code (mutation) that has reached a greater than 1% frequency in a local or global population. In genetic genealogy, we most often use it to describe backbone branch defining mutations. These are related to backbone haplogroups.

Single nucleotide polymorphism (SNP): a change in your DNA code at a specific point.

Triangulation: A method of determining the ancestral haplogroup of an ancestor using the DNA results of direct line descendants.

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