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Ancestry DNA Tests: How Accurate Are They?

By SEO

An ancestry DNA test uses a saliva sample to determine which areas of the world your DNA can be traced back to. DNA kits have become very popular during the last few years. This has led to many people having numerous questions. You may be wondering if your genetic information will be used for research or sold and how this impacts your privacy. You may also be concerned regarding the accuracy of this test or have numerous additional questions. The first thing you must realize is the question of your DNA is complex and there may not be a simple answer. The majority of people in the world have DNA from numerous different regions. You may perceive this combination as unique or you may see it is odd. Either way, you need to be open and prepared for a surprise.

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.

The Concerns of Data Being Sold

If you are concerned about your data being sold, your concern may be valid. In the past, records have been sold and de-anonymized. It is possible for genetic information to be used to find the name of the individual the DNA came from. This can happen regardless of whether or not your name was in the database. This scenario has occurred in the past.

The Possibility of Inaccuracies

This is a large amount of data not being used by services testing DNA. There are millions of SNP’s contained in your DNA. This type of testing only looks at specific variations. This requires between 100 and 300 AIM’s. This is a small fraction of the SNP’s differentiating DNA. This means if your test stated you are fifty percent European, it means only half of your SNP’s appear to be European. Another issue is certain markers used for ancestry information for any given test are only derived from either your Y chromosomes or your paternal line or your mitochondrial DNA or maternal line. When these markers are used, your test will be less accurate. Another flaw is the DNA testing services are obtaining DNA from the current populations in specific regions. This makes unsubstantiated conclusions that the people living in these areas hundreds of thousands of years in the past have had the same DNA for all these years.

Determining the Origins of a Specific Side of the Family

If you wanted to learn about a specific side of your family, you must consider your genetic markers. A good example is if an individual wanted to know the origins of the African-American part of the family. Some luck would be required to retrieve this information. This person may be able to learn the percentage of genetic markers that favorably match certain regions of Africa. This is dependent on if different regions can be distinguished by the AIM’s. The most commonly used African AIM’s for determining African ancestry come from West Africa.

If this individual used several different companies for DNA testing, they might get an idea as to their past origins based on the moderate or high similarities of the people currently living in different regions throughout Africa. This is only possible if the companies have established the correct reference populations. This person must understand their DNA is being matched to the current population as opposed to the people who occupied the region hundreds of years in the past. It is just as possible the results would state this African-American individual is 75 percent European. This is because the ancestry markers chosen are only for a small percentage of this individual’s DNA. The African population has a more genetic diversity in itself than a European population and an African population.

The Privacy Issues

The companies providing ancestry DNA tests are making most of their money from selling the genetic information as opposed to running the tests. Companies purchase this information to increase the size of their genetic databases. Nearly half the companies selling ancestry information are selling to more than just one company. These are sometimes pharmaceutical companies attempting to understand how specific human genome sections can help develop new drugs. Certain mutations will impact the effectiveness of these drugs. The original DNA sample is only destroyed by roughly ten percent of these companies. Most companies keep or sell the sample. This means it is both your data and saliva being sold.

If the company responsible for running your test is sold, whatever you signed loses significance due to the privacy policies of the company. Despite most of these privacy policies stating they will notify you of any changes, you would have to keep in constant contact with the company to ensure you were actually aware of these changes. The people willing to do this would be far and few between. Unfortunately, even if your name is not located within the database, this does not mean other databases cannot be used to determine your identity. In one specific case, a woman had a DNA test run. She found out she had a half-sibling. Although she was very excited about this news, this type of information would devastate numerous individuals.

The Results

Some of the companies providing ancestry DNA testing have an option that will reveal information regarding any individual with similar SNP’s. It is even possible to acquire a list of individuals who may be included in the ancestry of your family. Once permission has been given, they are able to contact you and you can contact them as well. This may sound entertaining and harmless at first, but raises a lot of questions about what information people may not be ready to hear. You may already know specifically where you come from. Now imagine if you found out your real mother was actually your grandmother. Perhaps you were raised as you birth mother’s sister. You have to ask yourself if you could handle that type of information. Prior to signing up for an ancestry DNA service, you must be aware of all the potential implications that may be revealed.

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