“The Accuracy of DNA Testing — This is one of the most common questions and the most difficult to answer. There are approximately forty companies currently offering DNA testing to determine genealogy and ethnicity. None of these companies have shared their data, no standards of accuracy have been agree on and independent scientists have not yet validated these methods. Some experts believe the results are valid, others feel they must be viewed with some skepticism. Once you receive your results, you must decide on the validity based on your knowledge of your family history.
“The Variation in Results — 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.”
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