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.
Because it is a genetic condition, hereditary hemochromatosis is present at birth. Many people with this condition never develop iron overload. Of those who do develop iron overload, only a small number develop symptoms. If men develop symptoms, they typically appear between 40 and 60 years of age. Women rarely develop symptoms, and when they do it tends to be after menopause.
The first kit I try is Thriva’s baseline test (£49), which, like all its products, checks your blood. The box arrives promptly enough (containing spring-loaded needles, a little collection tube, antiseptic wipes, plasters, etc), but there’s a problem. The idea is to prick your finger and massage blood into the tube, but I just end up making my fingers sore and what I get out barely smears the top of the phial. Maybe it’s just me, but it turns into a right faff. In the end, I take advantage of Thriva’s service to send someone out to take a sample of blood from my arm.
When asked about how database size affects ancestry results, David Nicholson, co-founder of Living DNA, told us, “The tests absolutely rely on the reference database. If you have Polish ancestry but there are no people in the database who are Polish, then what the test will do is show what the next closest group is next to Polish, like German or Eastern European ancestry.”
Of the 23 pairs of chromosomes in the human genome, 22 are autosomes. Most direct-to-consumer DNA tests look primarily at your autosomal DNA to determine your geographic ancestry percentages. This DNA is a mix of inherited DNA segments – half from each parent. Because everyone inherits at least one X chromosome from their mother, DNA tests often include the X chromosome in autosomal testing, though the X chromosome is not an autosome.
Since genome sequencing is still a relatively young science, we don't recommend submitting your child’s DNA to direct-to-consumer companies. We do encourage consulting with your doctor about genetic testing for your child. Due to some concerns with the DNA testing industry, the choice to have one’s genes sequenced by a private company should be made with informed consent. Those concerns are magnified when applied to children, who cannot make their own decisions regarding the unlikely potential risks or privacy concerns.
DNA test companies that use genotyping technology, including 23andMe and Ancestry, allow you to download your raw DNA file. A raw DNA file is usually a text file that contains all the information about your genetic code gleaned from the company’s examination of your DNA. This is comprised of several hundred thousand markers known as SNPs (Single Nucleotide Polymorphisms). Most raw files are organized into five columns: the SNP coded into an rsID number, the chromosome the SNP is located on, the location of the SNP on the chromosome and the two alleles for each SNP.
In the case of a great-grandchild, or a great-great-grandchild, something even stranger can happen. Remember that a child will get half of their mother’s DNA, but there is never ever guarantee which 50%. The way it is chosen is fairly random, as far as scientists know. Take the example of the 100% Eastern European person. Their great-grandchild will inherit 50% of their DNA from their part-Eastern European parent, but there is a good chance that they won’t inherit all of the Eastern European DNA that they could potentially inherit. It’s possible for a person to share NO DNA with a great-great grandparent, even though there is a verified genealogical relationship.