DNA Testing: Your Genes Know You Better Than You Know Yourself

Photo courtesy of Bietenduevel via Wikimedia Commons

A lot can be sussed about your health, physical makeup, and more– all from a simple gene test.

By taking a sample from a person’s hair, skin, blood or other fluid, laboratory technicians are able to analyze chromosomes, DNA, and proteins.

Sure, a tiny piece of hair or glob of spit may seem insubstantial. But on a microscopic level genes can tell many stories about an individual’s past, present, and future — kind of like fortune telling, but backed up by modern science and medicine instead of tea leaves.

Uses of DNA testing

Genetic tests are useful for a number of reasons, which are growing as medicine accelerates and new discoveries are surfaced.

Traditionally, such tests were used starting in the 1950s to detect genetic conditions such as Downs syndrome and cystic fibrosis, ensuring early treatment for newborns especially.

Now, over 1,000 types of genetic tests are available for about 2,000 rare and common conditions. Some regular uses today are:

  • detection of gene mutations, changes, and variation that can cause disease or be passed down to others
  • pre-identification of gender, diseases, or gene variations in unborn fetuses or newborns
  • determining paternity and ancestry
  • helping to convict criminals with DNA evidence
  • matching patients to appropriate medicine and therapy and personalizing treatment to their genetic makeup

New and surprising gene identifications

There are some conditions that years ago would have been thought entirely environmental, if considered conditions at all, that we now know are genetically predisposed.

For example:

  • obesity: FTO and BDNF genes have been found to play a role in eating habits that lead to obesity
  • alcoholism: among other evidence, the DRD2 gene has been shown to contribute to alcoholism and addictive behavior.
  • suicide risk: John Hopkins researchers found an alteration in the SKA2 gene that could indicate suicidal thoughts in individuals, and could possibly be used to identify risk of suicide in soldiers or patients through blood tests.
  • other illness: a 2013 study found that patients with depression, schizophrenia, autism, and ADHD had the same variations in their genetic code compared to those without
  • violence: variations in the MAOA gene have been linked to violent and antisocial behavior, in extremely high rates if individuals had also suffered abuse

And then there are other genetic predispositions, like social and romantic preferences, that aren’t medical conditions at all — for example:

  • homosexuality: scientists found that genes on at least to two chromosomes affected whether men were gay or straight
  • romantic preference: people tend to literally sniff out genetically compatible partners without knowing it based on the immune system. There’s even such a thing as genetic matchmaking.
  • friendship: people have been found to be more genetically similar to their friends than to strangers — about as genetically similar as fourth cousins, in fact.

Personality traits and talents are also genetically predisposed, though researchers are further from being able to detect these as they are likely a combination of various genetic factors.

Ethical issues

There is still much to be known about genetic makeup, but as DNA testing becomes more advanced there are concerns over what to make of the results.

For one, it could be a privacy issue — some are worried that having a person’s genes on file could lead to use and misuse of such personal information.

Prenatal DNA testing also raises the concern of parents’ willingness to act on the limited information they’re provided with about their future child. After all, genes only tell part of the story.

Another issue is that with the detection of specific genes may inevitably come the ability to select and tweak them, which has folks worried we’re creeping toward eugenics.

So while a genetic test is perhaps more reliable than a crystal ball, to trust it wholeheartedly or worse, abuse its revelations in the hopes of perfection, could lead to problems down the line.

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Jennifer Markert