CRISPR-Cas9技術は、特定の遺伝子を精密に編集できる革新的な技術です。これにより、遺伝子疾患の治療が可能になると期待されています。例えば、鎌状赤血球症やβサラセミアの治療において、CRISPRを用いた臨床試験が進行中です（参考: New England Journal of Medicine）。
(2) 倫理的・社会的課題
遺伝子編集が可能になることで、「デザイナーベビー」の問題や、遺伝子操作の倫理的な制限について議論が続いています。例えば、一部の国では生殖細胞系列の編集は禁止されていますが、技術の進歩によって規制のあり方も変化する可能性があります（参考: WHO – Human Genome Editing）。
8. 遺伝子検査とメンタルヘルスの関係
遺伝子がメンタルヘルスにも影響を及ぼす可能性があることが研究によって明らかになっています。
(1) うつ病・不安障害と遺伝子
例えば、**5-HTTLPR（セロトニントランスポーター遺伝子多型）**は、ストレス耐性やうつ病リスクに関連するとされています。短いバリアント（S型）を持つ人は、ストレス環境下でうつ病を発症しやすい可能性があるという研究結果があります（参考: American Journal of Psychiatry）。
In recent years, genetic testing technology has advanced rapidly, and it is attracting attention as a way to provide information that is useful for personal health management, root search, and even disease risk assessment. However, there are some important points to understand before undergoing genetic testing. This article explains five important points that people who are interested in genes and experts in genetics should know before undergoing genetic testing.
1. There are many different types of genetic tests
Genetic testing can be categorized into several types depending on the purpose and method. Before undergoing a test, it is important to choose the test that best suits the information you are looking for.
(1) Genetic testing related to health and disease risks
This type of testing is done to assess a woman’s risk for certain diseases. For example, mutations in the BRCA1/BRCA2 genes are known to be associated with a higher risk of breast and ovarian cancer (source: National Cancer Institute).
(2) Genetic testing for ancestry and family history
This test is conducted to explore one’s ancestral roots. By examining the Y chromosome and mitochondrial DNA, it is possible to trace paternal and maternal lineage.
(3) Pharmacogenetic testing (pharmacogenomics)
This test is used to evaluate drug metabolism and the risk of side effects based on an individual’s genetic information. For example, it is known that mutations in the CYP2C19 gene affect the effectiveness of certain drugs (e.g., clopidogrel) (Reference: PharmGKB ).
2. Understand the accuracy and limitations of genetic testing
Genetic testing is a powerful tool, but it can be dangerous to place too much faith in its results.
(1) Relationship between genes and environmental factors
Many diseases develop through interactions between genetic factors and environmental factors (diet, exercise, stress, etc.). For example, research has shown that even if you have an obesity-related FTO gene mutation, you can reduce your risk by maintaining a healthy lifestyle (Reference: Nature Genetics ).
(2) Possibility of false positives and false negatives
Genetic tests can occasionally produce false positives. In particular, commercially available genetic test kits may be less accurate than laboratory tests in assessing the risk of certain diseases. Therefore, it is important to consult with a medical professional before making any medical decisions based on the results.
3. Genetic Information Privacy and Ethical Issues
Genetic information is highly sensitive personal data and requires careful management.
(1) Handling of genetic information and protection of privacy
Some companies that provide genetic testing may share or sell test data to third parties . For example, in 2018, it was reported that 23andMe was providing customer data to pharmaceutical companies (Source: Forbes).
(2) Impact on insurance and employment
In some countries, genetic information may be used to restrict insurance coverage or subject to employment discrimination. For example, in the United States, the Genetic Information Nondiscrimination Act (GINA) prohibits employers and health insurance companies from discriminating against people who use genetic information (see EEOC).
4. How should genetic test results be used?
How you interpret and use the test results is important.
(1) Use of genetic counseling
It is recommended that you seek advice from a genetic counselor or specialist to properly understand the results of your test . For example, if you are found to be at high risk for breast cancer, you can take specific measures, such as strengthening early screening (Reference: National Society of Genetic Counselors ).
(2) Test results can be used over the long term
Because your genetic information remains constant throughout your life, once you have been tested, you can receive additional information in the future as new medical research advances.
5. Genetic testing costs and selection
The cost of genetic testing varies widely.
(1) Estimated cost of genetic testing
A typical genetic test for consumers costs around 10,000 to several tens of thousands of yen , but precise genetic analysis conducted at a medical institution can cost hundreds of thousands of yen or more.
(2) Key points for choosing the right testing company
Test accuracy and reliability: Is the analysis based on scientific evidence?
Data handling policy: Check the privacy policy
After-sales service: Do they offer support regarding results?
Choosing a reputable company or institution is key to maximizing the value of your genetic testing.
6. Relationship between genetic testing and lifestyle
Genetic testing is a useful means of learning about one’s constitution and health risks, but how to make the most of it is important.
(1) The relationship between nutrition and genes (nutrigenomics)
“Nutrigenomics” is the field that studies the relationship between genes and diet. For example, it is known that mutations in the MTHFR gene lead to a lower than normal metabolism of folic acid, which increases the health risks associated with folic acid deficiency (Reference: National Library of Medicine ).
Mutations in the LCT gene are also known to increase the risk of lactose intolerance, which means that consuming dairy products can cause indigestion and abdominal pain (Source: European Journal of Human Genetics ).
(2) Genes and athletic aptitude (sports genetics)
It is known that genes affect muscle structure and endurance. For example, it has been studied that variants of the ACTN3 gene affect the development of fast-twitch muscle fibers, which determines whether an athlete is suited to sprinting or endurance running (Reference: Journal of Applied Physiology).
By utilizing genetic testing, you can design an exercise program that is right for you, making your training more effective.
7. Gene editing technology and the future of medicine
In parallel with advances in genetic testing, gene editing technology has also made great advances.
(1) Development of CRISPR technology
CRISPR-Cas9 technology is an innovative technology that allows precise editing of specific genes. It is expected that this will enable the treatment of genetic diseases. For example, clinical trials using CRISPR are underway to treat sickle cell disease and beta thalassemia (Reference: New England Journal of Medicine).
(2) Ethical and social issues
The possibility of gene editing has sparked ongoing debate over the issue of “designer babies” and the ethical limitations of genetic manipulation. For example, germline editing is prohibited in some countries, but technological advances could lead to changes in regulations (see WHO – Human Genome Editing ).
8. The relationship between genetic testing and mental health
Research has shown that genes can also influence mental health.
(1) Depression, anxiety and genes
For example, **5-HTTLPR (serotonin transporter gene polymorphism) ** is said to be related to stress resistance and depression risk. Research has shown that people with a short variant (S type) may be more likely to develop depression under stressful circumstances (Reference: American Journal of Psychiatry).
In addition, genes related to the risk of bipolar disorder include CACNA1C and ANK3 . It has been pointed out that mutations in these genes may lead to difficulties controlling emotions (Reference: Nature Genetics ).
(2) Genetic and environmental factors of mental illness
Although genetic factors in mental health are important, environmental factors (stress, trauma, interpersonal relationships, etc.) also have a significant impact, so genes alone cannot predict the onset of mental illness. Therefore, it is recommended not to rely too much on the results of genetic testing and to take comprehensive care.
9. Genetic testing regulations and international trends
As genetic testing becomes more widespread, different countries have different regulations.
(1) Regulation of genetic testing in Japan
In Japan, clear laws regarding genetic testing are still in the process of being established, but genetic diagnosis at medical institutions is regulated based on the **Guidelines for Optimizing Genetic Medical Treatment**.
In addition, with regard to consumer genetic testing, the Japan Society of Human Genetics and the Ministry of Health, Labor and Welfare have formulated guidelines, and a system has been put in place to certify trustworthy businesses (Reference: Japan Society of Human Genetics ).
(2) Genetic testing regulations overseas
In the United States, the FDA (Food and Drug Administration) regulates the approval of genetic tests, and some tests are only available through medical institutions.
EU: Genetic testing is primarily used in medical and research institutions, and regulations for consumers tend to be stricter.
It is important to understand these regulations and make sure any genetic tests you undergo are properly managed.
10. The relationship between genetic testing and longevity
In recent years, research into the relationship between genes and lifespan has progressed, and it has become clear that certain genes affect longevity.
(1) Genes related to longevity
FOXO3 gene: People with certain mutations in this gene have been reported to be more likely to live longer, healthier lives (Source: Proceedings of the National Academy of Sciences).
SIRT1 gene: Also known as the sirtuin gene, it is believed to be involved in suppressing cellular aging and DNA repair. Research is ongoing into this gene as one of the keys to longevity (Reference: Nature Reviews Molecular Cell Biology ).
(2) Lifespan is not determined by genes alone
Genetics is thought to account for about 30% of longevity, while the remaining 70% is due to environmental factors and lifestyle choices. Proper diet, exercise, and stress management are essential for longevity.
11. Genetic testing and allergies
Genetics also plays a role in your risk of developing allergies.
(1) Genes associated with allergic diseases
HLA genes: Involved in regulating autoimmune responses, certain mutations are believed to be associated with hay fever and food allergies (Reference: Journal of Allergy and Clinical Immunology ).
IL-13 gene: Research has shown that it increases the risk of asthma and atopic dermatitis (Reference: European Journal of Immunology ).
(2) Limitations of genetic testing for predicting allergy risk
It is not possible to predict the onset of allergies 100% based on genetic information alone. Because there is a large interaction with environmental factors (diet, air pollution, stress, etc.), a comprehensive judgment is required.
12. Genetic testing and cancer risk assessment
Genetic factors play a role in the development of cancer.
(1) Major genes associated with cancer
BRCA1/BRCA2 genes: Genes that increase the risk of developing breast cancer and ovarian cancer (Reference: National Cancer Institute).
TP53 gene: A gene that suppresses the cancerization of cells, and mutations in it increase the risk of various cancers (Reference: Cell ).
(2) Preventive measures using genetic testing
By learning about your cancer risk in advance through genetic testing, you can take measures such as increasing the frequency of regular checkups and improving your lifestyle.
13. Psychological impact of genetic test results
Genetic test results may affect the psychological state of the individual who receives them.
(1) Positive impact
Leads to improved lifestyle habits
Motivates people to take preventive medical measures
(2) Negative effects
Knowing that you are “prone to getting sick” increases your anxiety
Psychiatric disorders: Optimization of pharmacotherapy (e.g., differences in antidepressant metabolism due to CYP2D6 gene variants).
(2) Preventive medicine using genetic information
It makes it possible to manage health according to individual risks, contributing to the development of preventive medicine.
15. Precautions when undergoing genetic testing
Before undergoing genetic testing, it is important to know the following:
(1) Verify the reliability of the test
Is the test based on scientific evidence?
Are there any affiliations with research or medical institutions?
(2) How to interpret the test results
Not 100% definitive
Use in consultation with medical professionals
(3) Protection of genetic information
Check the data handling policy
Check whether information is provided to a third party
16. Relationship between genetic testing and infertility treatment
Genetics also influences your fertility and risk of infertility.
(1) Genes associated with infertility
AMH (anti-Mullerian hormone) gene : Related to ovarian reserve (number of eggs) and used to assess the risk of premature menopause (Reference: Human Reproduction).
FSHB gene : Involved in the secretion of follicle-stimulating hormone, and has been linked to polycystic ovary syndrome (PCOS) (Reference: The Journal of Clinical Endocrinology & Metabolism).
(2) Male infertility and genes
Y chromosome microdeletion (AZF region) : Involved in spermatogenesis, deletion in this region increases the risk of azoospermia (see Fertility and Sterility ).
CFTR gene : Associated with cystic fibrosis and may contribute to azoospermia (Reference: Genetics in Medicine ).
When considering infertility treatment, genetic testing may help you select the appropriate treatment method.
17. The relationship between genetic testing and skin type/beauty
Research has shown that genes influence skin aging and beauty.
MMP1 gene: Encodes a collagen-degrading enzyme and is associated with UV-induced skin damage (Reference: Experimental Dermatology ).
(2) The relationship between beauty and nutrients
Since nutrient metabolism differs depending on genes, it becomes possible to select skin care products and supplements that are tailored to each individual.
Genetic testing can help you implement more effective beauty measures.
18. Genetic testing and alcohol/caffeine tolerance
Your genes affect your ability to metabolize alcohol and caffeine.
(1) Genes related to alcohol metabolism
ALDH2 gene : Involved in alcohol metabolism, mutations in this gene make people more likely to be “alcohol-sensitive” (see: Alcohol and Alcoholism).
ADH1B gene : Involved in the rate at which alcohol is broken down, and mutations in the gene make the person more susceptible to the effects of alcohol (Reference: Pharmacogenomics Journal ).
(2) Genes associated with caffeine tolerance
CYP1A2 gene: Determines the rate at which caffeine is metabolized, with there being rapid and slow metabolizers (Reference: Clinical Pharmacology & Therapeutics ).
ADORA2A gene: Involved in the stimulating effect of caffeine and may increase the risk of insomnia (Reference: Sleep Journal).
By undergoing genetic testing, you can tailor your alcohol and caffeine intake to suit your constitution.
19. Genetic testing and immune function
Immune function is also influenced by genetics.
(1) Genes related to immune function
HLA genes: Determine susceptibility to autoimmune diseases and infectious diseases (Reference: Immunity).
TLR genes: Regulate the innate immune system and affect the risk of infectious diseases (Reference: Nature Immunology ).
(2) Vaccine effectiveness and genes
Responses to vaccines also vary by gene. For example, the IL-28B gene has been reported to be involved in the effectiveness of influenza vaccines (Reference: The Lancet Infectious Diseases).
20. Genetic testing and food digestion ability
Your genes determine how easily you can digest certain foods.
(1) Lactose intolerance and genes
LCT gene: This gene is involved in the ability to produce an enzyme that breaks down lactose, and if the gene is mutated, it becomes difficult to digest milk (Reference: American Journal of Clinical Nutrition).
It has been scientifically proven that genetic factors influence food preferences and taste perception.
22. Relationship between genetic testing and driving ability
There is research being done into the possibility that genes may influence how good or bad a driver you are at driving.
(1) Spatial ability and genes
BDNF gene : This gene encodes Brain-Derived Neurotrophic Factor and is involved in memory and learning. People with certain mutations in this gene are said to be more likely to have impaired spatial awareness and make driving errors (Reference: Journal of Neuroscience ).
(2) Reaction rate and genes
DRD4 gene: Involved in dopamine receptors, affecting concentration and impulsivity. People with certain mutations may be more inattentive and may have delayed hazard recognition while driving (Reference: Nature Neuroscience ).
Genetic testing can help you understand the characteristics of your cognitive abilities and become a safer driver.
23. Genetic testing and social/interpersonal relationships
It has also been found that genes play a role in whether or not one is good at interpersonal relationships.
(1) Sociability and genes
OXTR gene : Involved in the oxytocin receptor, it affects empathy and sociability. Mutations in this gene may affect how people interact with others (reference: Psychoneuroendocrinology ).
(2) Stress tolerance and genes
COMT gene: Involved in stress response, research has shown that mutations in the COMT gene make some people more stress-resistant than others (Reference: Biological Psychiatry ).
Knowing your genetic characteristics can help you manage stress and improve communication.
Summary
Genetic testing is a powerful tool that can help with health management, disease risk assessment, and lifestyle optimization, but its use requires careful understanding.
First, there are various types of genetic tests, and it is important to choose the appropriate one according to the purpose, such as disease risk assessment, ancestry analysis, confirmation of drug metabolism, etc. In addition, genetic information alone does not determine the onset of disease, and interactions with lifestyle habits and environmental factors must be taken into consideration.
In addition, genetic information is very sensitive personal data, and attention must be paid to privacy protection and ethical issues. It is recommended that you check the data management policy of the company providing the test and consult with an expert if you have any concerns.
How you use the results of your genetic testing is up to you, but using them to make medical and lifestyle improvements could help you live a healthier life.
