As discussed earlier, in order to determine the ethnicities present in your genetic make-up, genetic ancestry companies can analyse your autosomal DNA to seek out the genetic variants uniquely associated to certain population groups. These groups are known as ‘reference populations’, and they’ve been constructed by sampling the DNA of modern populations around the world, as well as from human remains at various archaeological sites. By identifying these genetic variants in your genetic code, companies can report on the groups that have contributed to your DNA.
There are a number of reasons why the vast majority of living humans are a blend of ethnicities. Firstly, from around 1850 onwards, people started to migrate around the world and mix in large numbers. Secondly, as national borders have changed over time, the only clear cut ethnic groups are those that are highly isolated. For example, as individuals have migrated in large numbers between France and Britain in the last few thousand years; those in Northern France exhibit a similar ethnic mix to those in Southern England.
Admixture percentages are one of the biggest reasons people choose to have their DNA tested. This report attempts to accurately match your DNA with population samples from around the world to tell you where your ancestors came from. Each of these companies has strengths and weaknesses when it comes to this calculation, and in the reports it provides to users.
While 23andMe does offer DNA relative matching and some tools to compare your genes to your DNA relatives, it doesn’t have robust genealogy tools, as its focus rests more in personal discovery and exploration. To that end, 23andMe has an optional health upgrade that provides reports on DNA traits like hair color and genetic predispositions to certain illnesses and diseases. It is the only DNA test with FDA approval for testing genes linked to conditions such as Type 2 diabetes, certain types of cancer, late-onset Alzheimer’s disease and Parkinson’s disease. If you’re interested in the health portion of the test, we recommend buying the Health + Ancestry test together, as this option costs less than upgrading later.
Most companies will use algorithms to compare the genetic variants uniquely associated to a reference population with those identified in the person being tested. This can help them exclude unlikely population groups from your ethnic mix, and ensure that the ethnic groups you’re shown to be composed of are more accurately reported. Although most companies will share the reference populations they use with their customers, they rarely provide information on the algorithms they’ve developed.
ARSACS Agenesis of the Corpus Callosum with Peripheral Neuropathy Autosomal Recessive Polycystic Kidney Disease Beta Thalassemia and Related Hemoglobinopathies Bloom Syndrome Canavan Disease Congenital Disorder of Glycosylation Type 1a (PMM2-CDG) Cystic Fibrosis D-Bifunctional Protein Deficiency Dihydrolipoamide Dehydrogenase Deficiency Familial Dysautonomia Familial Hyperinsulinism (ABCC8-Related) Familial Mediterranean Fever Fanconi Anemia Group C GRACILE Syndrome Gaucher Disease Type 1 Glycogen Storage Disease Type Ia Glycogen Storage Disease Type Ib Hereditary Fructose Intolerance Herlitz Junctional Epidermolysis Bullosa (LAMB3-Related) Leigh Syndrome, French Canadian Type Limb-Girdle Muscular Dystrophy Type 2D Limb-Girdle Muscular Dystrophy Type 2E Limb-Girdle Muscular Dystrophy Type 2I MCAD Deficiency Maple Syrup Urine Disease Type 1B Mucolipidosis Type IV Neuronal Ceroid Lipofuscinosis (CLN5-Related) Neuronal Ceroid Lipofuscinosis (PPT1-Related) Niemann-Pick Disease Type A Nijmegen Breakage Syndrome Nonsyndromic Hearing Loss and Deafness, DFNB1 (GJB2-Related) Pendred Syndrome and DFNB4 Hearing Loss (SLC26A4-Related) Phenylketonuria and Related Disorders Primary Hyperoxaluria Type 2 Rhizomelic Chondrodysplasia Punctata Type 1 Salla Disease Sickle Cell Anemia Sjögren-Larsson Syndrome Tay-Sachs Disease Tyrosinemia Type I Usher Syndrome Type 1F Usher Syndrome Type 3A Zellweger Syndrome Spectrum (PEX1-Related)
Companies like Embark, Wisdom Panel and many others offer genetic health risk screenings, trait analyses and breed percentage information for dogs. These canine ancestry tests allow you to confidently state that your mutt is part Irish wolf hound and give you key information about your pet’s heritage for insights into potential health issues. For example, if you find out one of your rescue dog’s parents was likely a purebred boxer, you could speak with your vet about breed-specific needs. Basepaws DNA CatKit promises information about your cat’s breed and traits with just a hair sample, though it offers swab kits for hairless cats. The kit also tells you how closely related your kitty is to wild cats like lions, tigers and ocelots.
FTDNA has the most advanced tools for easily analyzing cousin matches as of now, although it is possible that MyHeritage DNA may catch up. They seem very eager to please customers at this point. FTDNA does fall short when it comes to the ability to sync with developed family trees however. This is certainly not intentional on their part, they have developed some great tools for this purpose, but FTDNA (unlike Ancestry and MyHeritage) does not provide record searches or an online family tree program for the purpose of genealogical research. For this reason they are inherently limited in this regard.
Nacho Esteban of 24Genetics told us, “Ancestry is not an exact science. The top five companies in the world would show very similar results when talking about continents; the similarity is smaller when talking about countries. In regional ancestry, some border regions are difficult to identify and sometimes there may be discrepancies. So we cannot take the information as something 100% sure. But at the end, it gives a great picture of where our ancestors were from.”
The results of mixed DNA profiles may therefore provide reduced match probabilities when compared with non-mixed profiles. It may be possible for a scientist to be able to assess the relative amount of DNA contributed by different donors in a DNA mixture. If one person has contributed a clear and distinct majority of the DNA detected, that part of the profile may be referred to as the “Major Contribution”.
There's a lot you can learn from a DNA test. In addition to deepening your understanding of ancestry, some services will introduce you to relatives around the world or shed light on your predisposition to specific health issues and diseases. Here we present to you our roundup of the nine top DNA testing kits and services -- what they offer, how they work and how much they cost.
Four testers took 23andMe DNA kits during testing. We received our results 32 days later, and testers were highly satisfied with the overall experience, from ease of sample collection to the thoroughness of the results. Recently, the company updated its database and increased the number of geographic regions from around 170 to more than 1,000. The updated ancestry reports are also more detailed, especially for non-European regions. 23andMe’s ancestry tests give you information split into several different reports spanning your ancestry composition, maternal and paternal haplogroups, neanderthal ancestry and DNA family. Testers particularly liked the timeline feature, which estimates when your most recent ancestor lived in each of your matched regions.
Whole genome sequencing is the most accurate representation of your DNA that you can buy, as it provides you with the details of every single base in your DNA (more than 5 billion). This is unsurprisingly much more expensive than DNA profiling, and isn’t necessary if you are looking for a profile for identification purposes. However, if you’d like to know more about DNA sequencing, we’ve listed the companies that can sell you your sequence.
Y-DNA Tests: Y-DNA testing examines the Y chromosome passed only from father to son and can therefore be used to gain a better understanding of your paternal line. This can be a very interesting study for those focused on surname research, especially since the Y chromosome can give information about deep and recent roots. Because only men carry this chromosome women will need to test their father, brother or other male relation to use this test for genealogy purposes. Again, FTDNA is the leader in this type of testing and has a wealth of information, groups and forums to help.