How Does Home Genetic Testing Work?

Before you go to compare the best DNA kit you may want to learn how do DNA ancestry and genetic health mapping works in practice. We will try to stick to layman terms and explain the concept as plainly as we possibly can. Needless to say, genetic testing is a very complex branch of science that has been evolving tremendously over the decade or two; it took scientists 13 years to complete the Human Genome Project, and hence we will not be able to give you the full lay-down but rather provide bits and pieces explaining how do home DNA kits work.

What is DNA? What is Genealogy? What is the Human Genome Project?

How Do Direct-to-Consumer Genetic Home Tests Work? What is Genetic Testing?

Many companies are now offering direct-to-consumer genetic home tests. These tests, like normal genetic tests performed through a medical professional, offer insights into the genetic code of your body. The results can be used to identify parts of that code which may increase your risk for certain diseases or conditions. They can also be used to trace your familial history.

Your genetic code is called DNA. DNA is a series of molecules contained within each one of your cells. These molecules carry genetic information, like a blueprint. This blueprint is built through the machinery of your cells, and your body is created and maintained.

Genetic testing allows scientists to read this blueprint. Within the DNA are specific parts of the blueprint, known as genes. Each gene contains the information necessary to build a specific protein. These protein molecules are biologically active, interacting with the environment and other molecules. Humans make around 20,000 of these proteins. The sum of all these proteins at work in their environment is YOU!

How do At-Home Genetics Tests Work?

Depending on the company providing the test, the exact procedure of the genetic test can differ. Typically, the company will mail you a kit with instructions for collecting genetic material. This may be a cheek swab, taking a small amount of cells from your cheek. This could also mean a small blood draw. The sample is then mailed to the laboratory, where it is analyzed.

To analyze your DNA, the laboratory will put it through a series of procedures. The machines involved will map the makeup of the DNA, down to the individual molecules which constitute the DNA chain. By comparing this composition to other genetic data, information about your personal genetics can be gleaned.

The company will then send you a personalized report with the results. Depending on the package you paid for, this may be as simple as a single gene, or as complex as your entire genetic code. While the direct-to-consumer tests often test for the same things as a genetic test through your doctor, they often focus on multiple genes within the vast DNA blueprint.

Genetic testing allows a person to take a peek into this vast blueprint. Doctors and other healthcare providers often order tests looking for specific genes and information related to disease. Direct-to-consumer testing often scans for a wide range of traits.

Types of At-Home Genetic Tests

Disease Risk and Health

These direct-to-consumer tests analyze genes causing several diseases, such as Parkinson disease and Alzheimer’s. These and other diseases are not caused directly by genes. However, some studies have correlated various genes to an increased likelihood of developing the disease. Genetic testing can also analyze genes related to certain cancers, though this is not definitive evidence that a person will develop cancer.

Because your DNA is just a blueprint, it is never definitive. The lifestyle choices you make (diet and exercise) greatly affect the expression of these blueprints. For instance, various genes are related to getting certain cancers. These genes can be expressed differently in someone who has a good diet and exercises regularly, versus a heavy smoker who never exercises. The latter is much more likely to develop cancer, regardless of genetic makeup.

In addition to testing for the above conditions, many tests also analyze your genome for genes that indicate you are a carrier for a specific conditions. These diseases only show up in patients with two recessive alleles, or copies, of the gene. If you carry a recessive allele, you will not have the disease. However, your children may inherit two recessive copies if your partner is also a carrier. Genetic testing can show you your carrier status for a number of genetic diseases, such as Tay-Sachs Disease and Sickle Cell Anemia.

A number of other genes can also be analyzed relating solely to inherited traits. These could be things like male pattern baldness, dimples, and even eye color. These traits are also stored genetically, and some are found on a single gene. This can inform you of your true genetic nature, and may inform you which alleles you may be able to pass to your children.

While direct-to-consumer genetic home tests can inform you of the genes present in you cells, it is important to discuss your personal results with a genetic consultant or doctor. Many direct-to-consumer genetic home tests offer some sort of consulting as part of their package. This option is very wise if you don’t understand genetics or the various effects the environment can have on genes.

Ancestry or Genealogy

Another common reason to take a direct-to-consumer genetic test is to better understand your family history and genealogy. While written records can often provide this information up to a few hundred years ago, your genetics paint a much more complete picture. By tracing the unique parts of DNA through various populations of people, scientists can identify groups you share a genetic heritage with.

These results often vary by company, and their accuracy has been heavily debated. Still, they can offer a unique insight into your heritage that written records will never be able to match. These tests are able to tell your deepest biological roots, and can detect DNA from a number of unique sources and identify the geographic locations those sources likely came from. Scientists have even been able to identify Neanderthal DNA sequences, from when our species was first becoming established.

Kinship

In similar testing, genetic tests can be used to prove paternity. In this case, both your DNA and that of your parents must be analyzed. You, as a matter of fact, are created half from your mother’s DNA and half from your fathers. This means that you will share 50% of your DNA with each of your parents. If one of your parents is not your biological parent, a genetic test will show this.

Paternity testing is much more accurate and informative than many kinds of DNA tests. Paternity testing is often used and accepted in court cases and custody hearings, as the results are clear and undeniable. If a person is not biologically related to you, the genetic paternity test will clearly show the differences between your genes.

Lifestyle

These direct-to-consumer home genetic tests are often based on the lowest scientific rigor. Many genetic testing companies offer services which claim to match your genetics to various services. These services could be weight-loss techniques, sleep patterns, or even foods you might enjoy based on your genetics. There are many of these services available, but their accuracy, procedures, and results are all questionable. These services often offer the least insight into your health, and are likely profiting by selling your data.

As genetic testing becomes more accurate and informative, these sorts of tests may gain more rigor and scientific backing. At the present, they are more of a gimmick than actual science. Any information gleaned by these tests should be taken with a grain of salt. While your genetics do play a role into what foods you might like and how you lose weight best, there is little evidence that someone can accurately identify these things looking solely at genetics. Much more important is your personal lifestyle choices and upbringing, especially in matters of preference and choice.

Should You Take an At-Home Genetic Test?

If you have a medical condition you are currently dealing with, or know for a fact that your family is prone to genetic conditions, you should consult a doctor. Direct-to-consumer tests are typically meant to add general understanding of your DNA, and should not be considered medical advice. Having a gene which predisposes you to cancer is NOT the same as having cancer. A genetic consultant can explain these personal anomalies in better detail.

As time goes on, these genetic tests will become more and more accurate. However, scientists are also finding that the environment surrounding your genes is much more important than the genes themselves. What you eat is the material your cells receive to grow and reproduce. The amount you exercise determines how active your cells are. Together, these can form a much stronger influence than your genetics alone.

If you choose to take a direct-to-consumer genetic home test, keep a few things in mind. First, the test is simply going to give a sneak-peek into your genetic blueprints. It should not be used as a definitive medical diagnosis. You genetics may predispose you to a condition, but it is the interaction with the environment that will determine the outcome.

The at-home tests can provide a wealth of information to learn more about yourself. They can inform you on whether you carry genes for male pattern baldness. They can tell you if you are a carrier for genetic diseases. Genetic tests can also inform you on your genetic heritage. If you want to know as much as you can about yourself and your family, direct-to-consumer genetic home tests are a good way to learn more.

There are now many companies offering various insight into your genetics. Choose a company offering the insights you wish to glean, check with other sources to ensure they are backed by rigorous science, and take their findings with a grain of salt. Direct-to-consumer genetic home tests are a powerful new tool for understanding your genetics. Just make sure you understand what the results mean.

Important Things to Consider Before Ordering a Test

Data Privacy

The privacy of your genetic data is not guaranteed when you take an at-home genetic test. Unlike your doctor, the companies offering these tests are usually also making money by selling parts of your data to researchers and other organizations.

If you do not want your data to be shared, be sure to research the company you plan to buy a genetic tests from. Some companies may offer complete privacy, while others may not. It is not illegal to sell this information, especially if you give your consent before taking the test. If you don’t want this information available to the whole world, make sure the company you choose will respect your wishes.

Inaccurate Results

In general, genetic testing is fairly accurate. However, some companies are better than others. Remember that you usually get what you pay for. A cheaper test may save you a few dollars, but it also may be highly inaccurate.

Further, a number of conditions and tests offered by genetic testing companies are not backed by science. A test pairing your genetics to various flavors of cheese likely has no grounding whatsoever in actual science. Some of the better genetic testing companies pair their tests with a consultation from a geneticist or doctor. This is highly advisable, considering the complexity of DNA and its interaction with the environment.

References

  1. Direct-to-consumer Genetic Testing | AMA. (n.d.). Retrieved November 29, 2018, from https://www.ama-assn.org/content/direct-consumer-genetic-testing
  2. Five Things to Know about Direct-to-Consumer Genetic Tests. (n.d.). Retrieved November 29, 2018, from https://www.hopkinsmedicine.org/news/articles/five-things-to-know-about-direct-to- consumer-genetic-tests
  3. NSGC > Genetic Testing > What is At-Home Genetic Testing? (n.d.). Retrieved November 29, 2018, from http://aboutgeneticcounselors.com/Genetic-Testing/What-is-At-Home-Genetic-Testing
  4. Reference, G. H. (n.d.). What is direct-to-consumer genetic testing? Retrieved November 29, 2018, from https://ghr.nlm.nih.gov/primer/dtcgenetictesting/directtoconsumer