Introducing the Differences, Advantages, and Disadvantages of "DNA Testing" and "Genetic Testing"!

What is "DNA Testing"?

Everyone inherits half of their DNA information from each parent, and this information never changes throughout life. Tests that use this DNA information for personal identification—to confirm parent-child biological relationships, or to identify individuals in criminal or infidelity investigations—are generally called DNA testing. DNA testing primarily analyzes repeating sequences called "STRs" (Short Tandem Repeats). Since the number of repeats in STRs varies from person to person, comparing multiple STR loci allows for extremely accurate identification of parent-child relationships and individuals [ref:3][ref:4].

In the field of forensic science, DNA testing is often used as decisive evidence in criminal investigations, and its evidentiary value in court is internationally recognized. In Japan's family courts as well, DNA test results are adopted as important evidence in paternity confirmation lawsuits and acknowledgment of paternity claims [ref:4].

What is "Genetic Testing"?

A gene refers to a region of DNA that carries genetic information, and tests that analyze this genetic information to examine disease risk, constitution, and innate abilities are generally called genetic testing. Humans are estimated to have about 20,000 to 25,000 genes, and it is known that variants in some of them are associated with specific disease risks and physical traits [ref:1][ref:5].

Genetic testing reads slight differences in DNA sequences called SNPs (single nucleotide polymorphisms) to assess risks for conditions such as cancer, diabetes, and heart disease, and to obtain information about physical traits such as alcohol metabolism capacity and caffeine sensitivity. In recent years, advances in genome-wide association studies (GWAS) have identified numerous SNPs associated with disease [ref:8].

Advantages of DNA Testing

The advantage of DNA testing is that it provides a result with nearly 100% probability when confirming biological relationships or identifying individuals [ref:3].

• Paternity testing can clearly determine whether a parent and child are biologically related
• Can serve as an opportunity to resolve a lifelong worry or anxiety in a short period of time
• Results can be used for legal procedures such as acknowledgment mediation, child support claims, and inheritance matters
• Samples can be collected using a non-invasive, painless method such as an oral swab (wiping the inside of the cheek with a cotton swab)
• Choosing a testing agency with international certification such as ISO9001 ensures highly reliable results

Taking paternity testing as an example, DNA testing scientifically proves a biological parent-child relationship, allowing long-held doubts and anxieties to be resolved objectively. In Japan's family courts as well, DNA test results are widely adopted as important evidence in determining parent-child relationships [ref:4].

Disadvantages of DNA Testing

The disadvantage of DNA testing is that "the result is not necessarily what you hope for." Since DNA testing is judged purely on the basis of DNA match or non-match, it can produce a result that is emotionally difficult for the person to accept [ref:3].

Specifically, you should understand in advance that the following kind of psychological burden may occur.

1. Deciding to undergo testing (psychological preparation)
2. Collecting and sending the sample
3. The waiting period until results arrive (which can involve anxiety and stress)
4. Receiving and accepting the results
5. Deciding on future actions based on the results (such as legal procedures)

We recommend approaching DNA testing with this mental preparation in mind. If you have concerns about how to cope with the results, consulting a counselor or specialist is also an effective option.

Advantages of Genetic Testing

The fact that environmental factors have a significant influence, in addition to genetic factors, means that genetic testing can serve as a trigger for improving your lifestyle habits.

• Understanding disease risk in advance can be an opportunity to review lifestyle habits such as diet, exercise, and sleep
• Can motivate you to see a doctor, potentially leading to early detection of disease
• Allows you to scientifically understand your own constitution (alcohol metabolism capacity, tendency toward obesity, nutrient absorption efficiency, etc.)
• Knowing your innate abilities and aptitudes can make it easier to choose a career, sport, or hobby
• Can provide information that indirectly helps with family health management as well

In recent years in particular, the concepts of "preventive medicine" and "precision medicine" (personalized medicine) have been spreading, and attention is being given to building personally optimized health strategies based on genetic testing results [ref:5][ref:9].

Disadvantages of Genetic Testing

A disadvantage of genetic testing is the possibility that disease risk information may end up being shared with family members or a partner. In other words, because genes are passed down, genetic information can affect bonds with family members and partners [ref:6].

For example, if a result shows a high risk for a certain hereditary disease, that information becomes relevant not only to the individual but also to blood relatives. It's advisable to discuss in advance, within the family, how far to share test results and how to receive them. In addition, the issue of "genetic discrimination"—where genetic test results affect insurance enrollment or employment—is being debated internationally, and legislation regarding the handling of personal genetic information is also being advanced in Japan [ref:9].