The DNA test thing is a scam as the results cannot have precision. I know where my recent ancestors came from and wanted to “test a DNA test”. My ancestry is 3/4 Spanish Valencian and 1/4 Spanish Ibizean (Ibiza): I have family papers and village names for my recent ancestors: they all have typical Spanish/Catalan names and I expected this to be reflected in my results.

AncestryDNA has the largest database to compare your results to when making matches, with 23andMe coming in second and FTDNA in fourth. MyHeritage DNA, although newer than the others, is catching up fast and numbers now surpass FTDNA. Current numbers can be seen in the chart above and are estimates based on available data. Each of these databases is growing, some of them quite rapidly.

Another key customer type could be people like myself, hurtling through middle age, perhaps just starting to feel the cold bony hand of mortality clamp down on their shoulder. People, who, in the past, may not have exactly prioritised their health, who are starting to wonder what may be in store for them and who are in the (“Hypochondriacs R Us”) market for some hard-core insight and advice.
If you have the Health + Ancestry Service you have access to the full 23andMe experience. If you only have the Ancestry Service, you can easily upgrade to the Health + Ancestry Service for £90 which gives you access to all 125+ reports on ancestry, traits and health. You are eligible to upgrade once you have received your Ancestry reports. To upgrade, log in to your 23andMe account and navigate to the Settings page. You will receive immediate access to your new health reports.
23andMe is a bit different in that many people have tested with their company for the health results and are not necessarily interested in genealogy or matching with relatives, even if they opted into this feature. That doesn’t mean you won’t get a good response when reaching out, but it may be less common than with the other testing companies. Recently 23andMe has been placing more focus on genealogical testing, however, so this is may be shifting.
Specific tests for your father’s family include ‘Y-DNA’ tests which focus on the ‘Y chromosomes’ in your cells’ nuclei, passed down from father to son. Specific tests for your mother’s family include ‘mtDNA’ tests which report on a subset of DNA found in the ‘mitochondria’ (your cells’ energy factories), passed down from mother to son or to daughter.
my husband and I had a DNA test with ancestry done 2 years ago then we had our adult daughters done 2018 at Christmas when we got the results back my husbands and my results had changed a lot. example I was 47% Ireland and 19% Great Britain it changed to Great Britian 66% and Ireland 34% why? I called them but they said they had just change there process , we did not send new dna either. 
The DNA tests we reviewed either require a saliva or cheek cell sample. Saliva-collecting kits include a tube that’s marked with a fill line and sample number. The tube often has a liquid-filled cap with a stabilizer that acts as a preservative to protect your DNA from degradation during transport. Cheek swab sample kits include one or two swabs for scraping the insides of your cheeks for 30 seconds to a minute to collect cheek cells and some sort of container to place the used swabs into after collection. This prevents contamination. Our testers found upsides to both types of kits but generally preferred saliva collection kits, even though they took longer.
The last ancestry-related report from 23andMe is your DNA Family. This report is separate from the relative matching feature, which you have to opt-in to. It tells you very generalized information about the people in the database who share segments of DNA with you, including states of residence, similar geographical ancestral regions and traits like the ability to wiggle your ears or whistle.
In my research into my Cruwys ancestors in Devon, I hit a brick wall trying to find William George Cruwys (born 1821), the brother of my great great grandfather, Thomas Cruwys (born 1831). William disappeared from English records after the 1841 census. I found a William of the right age in Prince Edward Island, Canada, but couldn’t find any records to confirm a link, though naming patterns provided a strong clue.
When STR profiling is carried out, the whole of the person’s DNA is not examined. Rather, specific regions (loci) of the DNA which are known to vary greatly between individuals are examined. These loci are areas of the DNA which contain varying numbers of repeating sequences known as short tandem repeats (STRs). It is the number of these repeating units which can differ between individuals. If there are differences between profiles obtained from different samples, the two samples cannot have come from the same person. If, however, the profiles match, then it follows that the samples could have originated from the same person or from any other person who happened to have the same STR profile.Â
In addition to showing geographic ancestry percentages, some direct-to-consumer DNA tests also include insights about physical traits like hair and eye color. With 23andMe, this trait information is mostly available in the upgraded Ancestry + Health kit, but some interesting tidbits can be found in the Your DNA Family report, which is available if you opt to participate in the DNA Relatives service. 
TTR-related hereditary amyloidosis typically develops in adulthood, but age of onset can vary widely. People with the V122I variant typically develop symptoms after the age of 60. People with the V30M variant can develop symptoms as early as their 20s or as late as their 90s, depending on ethnicity and family history. People with the T60A variant typically develop symptoms between 45 and 80 years of age.
Although, I have absolutely no British or Irish ancestry, I found my results extremely satisfying. I particularly appreciate that living DNA gives you a lot of ways to view your data. You can see your ancestry results as color-coded dots filling up a person’s silhouette, on a map, as a pie chart or on a timeline. All the graphics present the same set of data, but each has its own appeal. Within each graphic, you can also choose to view global or regional matches and cautious, standard or complete estimates, which each have a different level of detail and certainty.
Each testing provider uses one of two methods to take your DNA sample and neither require blood. Family Tree DNA and MyHeritage DNA both use a cheek swab method where the user gently scrapes the inside of their cheek. The swab is then placed in a vial and sealed. AncestryDNA and 23andMe use a saliva sample. Some people may have a hard time producing a saliva sample so this should be taken into consideration when deciding on which test to choose.
There is one really, really important thing to know about this estimate, however.  Each child inherits 50% of their DNA from each parent.  That means that 50% of their parents’ DNA does NOT get passed down to the child.  This can mean that a child of a 100% Eastern European person will only show 50% Eastern European DNA, and their grandchild will only show 25%, and their great-grandchild 12.5% – in a perfect scenario.

We each had two ancestors one generation ago, four ancestors two generations ago, and by the time we’ve gone back five generations, 32 ancestors have each contributed approximately 3% of our autosomal DNA! As an ethnicity test can’t show you how your autosomal segments have been passed from one generation to the next, trying to derive meaningful information about the ethnicities of your ancestors more than five generations ago is virtually impossible.

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.
In addition to its ancestry test, 23andMe also offers a cool health upgrade. The upgrade costs $125 if you add it after getting your ancestry results, so we recommend splurging and buying the $199 Health + Ancestry kit from the start and it often goes on sale. It was approved as the first direct-to-consumer genetic screening service by the FDA in 2015 for certain conditions including Parkinson’s disease and late-onset Alzheimer’s disease. Many of the service’s 87 health reports are much more lighthearted, however, including information about your probability of disliking cilantro, getting bit by mosquitos or having a longer index finger than ring finger.
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”.
Many people who submit their DNA to a direct-to-consumer company also upload their raw information to public databases like GEDmatch, which law enforcement can access. People upload their raw DNA data after taking another test, like those from 23andMe or Ancestry, to several open online DNA databases. Most companies do not release database information to law enforcement. However, a recent study found that, using publicly available data, it's possible to identify up to 60 percent of Americans with European heritage via third-cousin-or-closer DNA.
Some of our reports are about serious diseases that may not have an effective treatment or cure. Some people may be upset by learning about personal risks, and risks for family members who share DNA. 23andMe will not share your personal information with an insurance company without your explicit consent. Learn more about third party information sharing here.
While DNA contains material common to all humans, some portions are unique to each individual. These portions, or regions, contain two genetic types (alleles) that are inherited from the person’s mother and father. A person’s DNA profile is made by investigating a number of these regions. In a paternity test, for example, the mother’s DNA profile is compared with the child’s to find which half was passed on by the mother. The other half of the child’s DNA is then compared with the alleged father’s DNA profile. If they don’t match, the ‘father’ is excluded, which means he isn’t the father of that child. If the DNA profiles match, the ‘father’ is not excluded - which means there is a high probability (more than 99 per cent) that he is the father. DNA tests such as this can’t offer 100 per cent proof.
mtDNA Tests: These type of tests look at the DNA found in our cell’s mitochondria. Mitochondria is located in the cytoplasm of the cell (surrounding and separate from the nucleus where most DNA is found) and is therefore only inherited from your mother. This means that a mtDNA test can help you understand the ancestry of your maternal line only. The nature of this test option also limits it to the understanding of deep ancestry (not so helpful for genealogists)–although the more detailed the test, the more accurate and specific your results become. The most commonly used tests for this purpose can be found through Family Tree DNA (FTDNA) and they have a huge amount of helpful information on better understanding the science and genealogical significance of this method of genetic testing.