What does a DNA test tell you?

DNA analysis is a method of analyzing DNA (deoxyribonucleic acid) to determine genetic relationships and personal characteristics.

1. Confirmation of parent-child relationship

As one of the most commonly used methods, DNA testing is used to confirm parent-child relationships. This is because DNA is passed from parent to child, thus making the genetic linkage clear.

  • Paternity Test: DNA of the child and the father or mother can be compared to confirm the parent-child relationship. The results show a 99.99% probability of a parent-child relationship, and a near 0% result if there is no parent-child relationship.
  • Sibling Identification: Sibling relationships can also be verified. You can check the relationship between half-siblings, half-fathers, etc.
  • Grandparents: In cases where there are no parents, the relationship between grandparents and grandchildren can be verified.
  • Aunt/Uncle Identification: The relationship between an uncle or aunt and a nephew or niece can also be verified through DNA testing.

2. criminal investigation and forensic evaluation

DNA identification is widely used in criminal investigations and forensic science. DNA can be extracted from remains (blood, saliva, hair, skin fragments, etc.) left at a crime scene and matched with a suspect’s DNA to identify the perpetrator.

  • Personal Identification: DNA left at a crime scene is compared to the DNA of a suspect to determine if they are the same person; DNA profiling can identify individuals with an accuracy of parts per trillion.
  • Victim Identification: When a victim cannot be identified due to a disaster, accident, or crime, the DNA of the victim’s family members can be compared to the DNA of the deceased to confirm the victim’s identity.

3. Risk Assessment of Genetic Diseases

DNA testing is also used to analyze an individual’s genes to assess the risk of genetic diseases. Abnormalities in certain genes can confirm whether a person is susceptible to a particular disease.

  • Genetic disease risk assessment: Mutations in genes such as BRCA1 and BRCA2 are associated with an increased risk of breast and ovarian cancer.Testing for these gene mutations can help prevent or detect the disease early.
  • Genetic Counseling: If a person is at high genetic risk, risk management and preventive measures can be discussed through genetic counseling.

4. Ethnic and Ancestral Roots Research

DNA can also be analyzed to determine an individual’s ancestry and ethnic background. This is a method that uses specific genetic markers to investigate what region a person’s ancestors came from and what ethnic roots they have.

  • Determine your ancestral origins: find out which region or culture you have roots in and from which your ancestors came many generations ago.
  • Check your ethnic background: find out which ethnic group you belong to and how genetically mixed you are.

5. Health Care and Personalized Medicine

Through DNA analysis, it is possible to determine an individual’s health status and how medication works. This allows for personalized medical care (personalized medicine) that is suited to the individual’s constitution.

  • Confirmation of drug response: Based on genetic information, the body’s response to a particular drug can be confirmed. This reduces the risk of side effects and allows for optimal drug selection.
  • Understanding of body constitution: It is possible to know what one’s genetic make-up is (e.g., obesity, ability to break down alcohol, etc.) and to improve one’s lifestyle based on this information.

6. Other uses

In addition to confirming specific personal information and parent-child relationships, DNA analysis can be used for the following purposes

  • Twin Determination: is used to determine whether twins are identical or fraternal.Identical twins have identical DNA, while fraternal twins have different DNA.
  • DNA testing of pets: DNA testing is sometimes used to confirm a pet’s pedigree, parent-child relationship, and risk of genetic disease.

Summary

Because DNA testing is so accurate and reliable, it plays an important role in a variety of fields.

Supervisor of the article


Dr. Hiroshi Oka

Director of CAP Laboratory

Graduated from Keio University, Faculty of Medicine

Doctor of Medicine

Medical Doctor