Every company providing DNA testing has their own database of DNA samples. These are called AIM’s or ancestry informative markers. These markers were derived from the current populations of America, Asia, Europe and Africa. Every database is looking for a pair of genes located on a specific chromosome in a specific position. The way the DNA is evaluated is through the SNP’s or the single nucleotide polymorphisms. The SNP’s are chosen according to the frequency in a specific geographical population. Your SNP’s are compared to the most common SNP’s for the various populations in the company’s reference database. The results are not conclusive because they are based on common genetic variations. The probability for your DNA being from a certain country is based on a comparison between your DNA and the database. If you used a different company, they would have a different database. This means your results would most likely differ. According to studies, the lowest concordance is with individuals of South Asian, East Asian and Hispanic descent.
Although the project states that most participants won’t receive any useful information, patients will be told if something is found in their genome that is relevant to the treatment, explanation or diagnosis of their condition. They can also choose to learn if they have a genetic risk factor for another disease, such as the BRCA1 gene mutation that can cause breast cancer. Genomics England will only look for risk factors that are linked to a disease that can be treated or prevented. Untreatable conditions, such as Alzheimer’s, are not looked for.
All of this is way over my head and confusing! I am wanting to purchase as a gift for a friend. The information I would like for the test to show is : 1. lineage for mother and lineage for father. I am not sure lineage is the correct word?! 2. relatives …don’t know if there are companies that show relatives other than just cousins 3. way to contact relatives. If someone would be so kind to recommend what company would be the best I would appreciate it. I have narrowed it down based on reading about different companies to… Read more »
Hi Dianne, First thing first, thanks for your comment. “he only test that can give information about recent relatives ( 5 generations back only) is the autosomal test” – autosomal test is indeed a DNA test that gives you the info regarding your relatives, both from the paternal and maternal lineage. We clearly specified it in the article. Ancestry.com, our best-rated provider, offer this test in their Ancestry DNA test. Regarding the accuracy of the time frame you specified, there is indeed a diminishing marginal utility of accuracy as you go back deeper into the past (generation wise). According to one of our most trusted sources (University College of London), the accuracy is 10 generations back and not 5 as you specified (Please provide a source to your number, so we would be able to check it and revise if needed). 10 generation back is a quite long time span – 300 years (more or less). “The tests that say we are such-and-such % of this or that ethnicity isn’t very accurate because keep in mind, the wars and the spoils of wars that humans have been engaged in forever, mean we all have a mixture of genetic material from around the world” – Indeed, most of our ancestors were mixed due to historical events (wars, migration and etc.), but I don’t find how your statement is connected to the fact that this test is not accurate. DNA test is objective and gives you the naked facts. To conclude,