In recent years, genetic testing has been attracting a great deal of attention in the medical field. Analyzing an individual’s genetic information is expected to lead to early detection and prevention of disease, as well as the realization of personalized medicine. This article provides a detailed explanation of the basic concept of genetic testing, specific ways to use it, and the latest research trends.
What is genetic testing?
Genetic testing is a method of analyzing an individual’s DNA to detect specific gene mutations and polymorphisms. This makes it possible to assess the risk of genetic diseases and clarify susceptibility to certain diseases. In addition, detecting acquired genetic mutations such as cancer can help with early diagnosis and treatment decisions.
Types of Genetic Testing
Genetic tests are classified as follows according to their purpose and subject:
Diagnostic tests : Tests performed on symptomatic individuals to identify disease-causing genetic mutations, for example when a specific genetic disorder is suspected.
Predictive testing : Tests to assess the risk of developing a disease that may not have symptoms at present, but may develop in the future, such as when there is a family history of the disease.
Carrier testing : A test to determine whether you are a carrier of a genetic disease and to assess the risk of passing it on to your future children.
Prenatal testing : Tests done during pregnancy to detect genetic abnormalities in the fetus.
Genetic testing and early disease detection
Genetic testing plays an important role in the early detection of diseases, particularly in the case of cancer and lifestyle-related diseases, making it possible to grasp the risk before the onset of the disease and take appropriate preventive measures.
Early cancer detection
Cancer is a disease caused by gene mutations, and genetic testing can be used to assess the risk of cancer and detect it early. For example, mutations in genes such as BRCA1 and BRCA2 are known to increase the risk of breast cancer and ovarian cancer. People with these gene mutations are recommended to consider measures such as regular checkups and preventive surgery.
Additionally, research is underway to use a blood test known as liquid biopsy to detect tumor-derived DNA in the blood for early cancer diagnosis and monitoring of recurrence.
Genetic testing is also useful for assessing the risk of lifestyle-related diseases such as diabetes and high blood pressure. It has been revealed that certain gene polymorphisms are associated with the risk of developing these diseases, and understanding an individual’s risk through genetic testing makes it possible to review lifestyle habits and receive appropriate medical intervention at an early stage.
In the field of genetic testing, new research is being reported one after another as technology advances. In particular, the development of next-generation sequencing technology has made it possible to analyze large amounts of genetic information in a short period of time, which is expected to lead to more detailed risk assessments and the discovery of new biomarkers.
Additionally, clinical trials are underway to utilize liquid biopsy for early detection of cancer and to realize personalized medicine based on genetic information.
There are several challenges to overcome in the widespread adoption of genetic testing. First, specialized knowledge is required to interpret the test results, so there is a need to educate medical professionals and establish a system for genetic counseling. In addition, there are ethical and legal issues regarding the handling of genetic information, so it is necessary to formulate appropriate guidelines for protecting privacy and managing data.
It is hoped that in the future, these challenges will be overcome and genetic testing will become more accessible and reliable, which will greatly contribute to the early detection and prevention of disease and the realization of personalized medicine.
The evolution of genetic testing and personalized medicine
① Personalized medicine using genetic information
Personalized medicine is an approach that provides optimal treatment and preventive measures for individual patients based on genetic information. In conventional medicine, the same treatment was generally applied to patients with the same disease, but advances in genetic analysis technology have made it possible to tailor treatment to each individual patient.
Specific examples of personalized medicine
Personalized cancer treatment
The genetic mutations in cancer cells are analyzed and specific molecular targeted drugs are selected. For example, EGFR inhibitors (such as gefitinib) are effective for lung cancer patients with EGFR mutations .
Optimizing Drug Response
Because the rate at which drugs are metabolized and the risk of side effects vary depending on genetic factors, analysis of CYP450 genes makes it possible to adjust the dosage of anticancer drugs and antidepressants .
Cardiovascular disease risk management
Research suggests that people with PCSK9 gene mutations may benefit from cholesterol-lowering drugs other than statins (PCSK9 inhibitors) .
These approaches offer the potential to provide the safest, most effective treatments for patients. (Source: nejm.org)
② Genetic testing and rare disease diagnosis
Many rare diseases are caused by genetic factors. Conventional diagnosis requires various tests based on symptoms, and it can take several years to identify the disease. However, the introduction of next-generation sequencing (NGS) technology has made it possible to make a quicker and more accurate diagnosis.
Rare diseases that can be diagnosed by genetic testing
Muscular dystrophy (DMD gene mutation)
Marfan syndrome (FBN1 gene mutation)
Huntington’s disease (HTT gene mutation)
Genetic testing using NGS allows rapid identification of the causative genes of rare diseases, enabling early intervention and expanding options for treatment and lifestyle support. ( Reference: ncbi.nlm.nih.gov )
3) Genetic testing and infectious disease risk
Recent research has revealed that genes involved in immune response affect the severity of and recovery from infectious diseases .
Relationship between representative genes and infectious disease risk
HLA genes and risk of influenza severity
ACE2 gene and novel coronavirus (COVID-19)
IFITM3 gene and risk of SARS virus infection
It has been found that in COVID-19, mutations in the ACE2 gene change the viral receptor, leading to differences in susceptibility to infection and severity. It is hoped that this knowledge will lead to advances in personalized medicine for infectious diseases. ( Reference: nature.com )
④ Genetic testing and pregnancy/prenatal diagnosis
Genetic testing is also used for screening during pregnancy and prenatal diagnosis. In particular, advances in non-invasive prenatal testing (NIPT) technology have made it possible to detect chromosomal abnormalities such as Down syndrome with high accuracy by analyzing fetal DNA from the blood of pregnant women.
Features of NIPT
Can be performed by simply taking a blood sample from the mother (less stress on the fetus)
Highly accurate detection of Down syndrome (trisomy 21), Edwards syndrome (trisomy 18), etc.
Genetic counseling is provided based on the test results.
Advances in NIPT technology are making risk assessment during pregnancy more accurate and expanding prenatal care options. ( Source: prenataldiagnosis.com )
⑤ Genetic testing and sports performance
Genetic information is also being used to improve the performance of athletes. It has been found that mutations in the ACTN3 gene affect the type of muscle fiber, determining whether the muscles are suitable for sprinters (fast-twitch muscles) or endurance athletes (slow-twitch muscles) .
What sports genetic testing can tell you
Explosive power vs. endurance aptitude
Speeds muscle recovery and fatigue resistance
Injury risk assessment (collagen gene mutations)
This information makes it possible to create optimal training programs for individual athletes, contributing to the advancement of sports science. ( Source: sportsgenomics.com )
⑥ The future of genetic testing
Genetic testing technology is evolving rapidly and is expected to be applied in even more fields in the future.
Future Outlook
Integration of AI and genetic analysis
AI is used to analyze massive amounts of genomic data and predict disease risk in real time.
The spread of real-time genetic testing
Development of technology to continuously monitor genetic mutations in the body and instantly detect abnormalities.
Lower costs and faster adoption
Advances in genetic analysis technology are enabling more people to easily undergo genetic testing.
In particular, diagnostic technology that combines AI and genetic analysis is expected to dramatically improve the accuracy of disease prediction. ( Source: cell.com )
7. Genetic testing and risk assessment for mental illness
It is known that genetic information is also involved in the risk of developing mental illnesses such as depression and schizophrenia. Until now, it was thought that environmental factors were the main cause of mental illness, but recent research has revealed that genetic factors also have a significant impact on the risk of developing a mental illness .
Representative psychiatric disorders and associated genes
Depression
SLC6A4 gene (serotonin transporter gene): Affects stress resistance and is associated with the risk of developing depression.
BDNF gene (brain-derived neurotrophic factor): Regulates neuroplasticity and influences the effectiveness of antidepressants.
Schizophrenia
COMT gene : Regulates the breakdown of dopamine and is involved in cognitive function and psychiatric symptoms.
DISC1 gene : Involved in brain development and increases the risk of schizophrenia.
FKBP5 gene : Involved in regulating stress hormones and increases the risk of developing PTSD.
Genetic testing can help people identify their risk of mental illness in advance and help them manage stress and develop appropriate treatment plans . ( Source: nature.com )
⑧ Genetic information and allergies/autoimmune diseases
The development of allergies and autoimmune diseases involves a complex interplay of genetic and environmental factors. In particular, it is known that HLA gene polymorphisms greatly affect the risk of developing autoimmune diseases.
Allergy-related genes
IL4 gene : Involved in hay fever and atopic dermatitis, and promotes the production of IgE antibodies.
FLG gene : Regulates skin barrier function and increases the risk of atopic dermatitis.
Genes associated with autoimmune diseases
Rheumatoid arthritis
HLA-DR4 gene : This gene overactivates the autoimmune response, causing joint inflammation.
Type 1 diabetes
HLA-DR3/DR4 gene : An autoimmune reaction destroys pancreatic beta cells and reduces insulin secretion.
Celiac disease (gluten intolerance)
HLA-DQ2/DQ8 gene : Causes an abnormal immune response to gluten and promotes inflammation of the intestinal mucosa.
Genetic testing can assess the risk of allergies and autoimmune diseases, and by managing diet and adjusting the environment, it is possible to prevent the onset and aggravation of symptoms . ( Reference: ncbi.nlm.nih.gov )
9. Genetic testing and anti-aging
It is known that genetic factors play a major role in the rate of aging and longevity. In particular, the genes that determine the length of telomeres affect lifespan and the risk of age-related diseases.
Key genes involved in aging
TERT gene (telomerase reverse transcriptase)
Repairs telomeres and inhibits cellular aging. Mutations accelerate aging.
FOXO3 gene (longevity gene)
It removes active oxygen and is involved in longevity. People with certain polymorphisms have a high probability of living to be over 100 years old.
SIRT1 gene (sirtuin gene)
Calorie restriction stimulates and slows aging.
Genetic testing can be used to assess aging risk, and strategies to extend healthy lifespan can be implemented by consuming antioxidant foods, restricting calories, and practicing moderate exercise . ( Reference: sciencedirect.com )
10. The relationship between genetic testing and intestinal bacteria
Recent research has demonstrated that the gut microbiome has a profound impact on health and disease risk, and furthermore, genetics have been shown to influence the composition of gut bacteria .
Interactions between gut bacteria and genes
FMT2 gene and gut bacterial diversity
Influences gut bacterial composition and modulates risk of obesity and type 2 diabetes.
LCT genes and lactose digestibility
Mutations in the LCT gene affect the risk of lactose intolerance.
By examining the composition of gut bacteria, personalized probiotics and dietary treatments can be proposed, advancing risk management for digestive and metabolic diseases . (Source: gut.bmj.com)
⑪ Social and ethical issues regarding genetic testing
The widespread use of genetic testing also raises the following social and ethical challenges.
Privacy and Data Management
Strict data protection regulations are required to minimize the risk of genetic information leaking.
Preventing genetic discrimination
Legislation is needed to prevent discrimination based on genetic information in employment and insurance contracts.
Interpretation of test results and psychological impact
It is important to popularize genetic counseling by experts so that people do not misunderstand that “high genetic risk = guaranteed onset of the disease.”
The future task is to make the most of the benefits of genetic testing while carefully considering the ethical issues involved. ( Reference: genomeweb.com )
⑬ Optimizing sleep using genetic testing
Sleep quality and biological clock rhythms vary from person to person, with genes playing an important role: studies have shown that certain genetic variants influence the amount of sleep we get and our risk of sleep disorders.
Key sleep-related genes
PER3 gene (regulates the body clock)
Mutations determine whether one tends to be a “morning type” or a “night type.”
People with certain types of the mutation are more susceptible to the effects of sleep deprivation.
CLOCK gene (regulation of circadian rhythm)
Regulate your sleep rhythm and determine your susceptibility to irregular lifestyle habits.
Mutations affect how easily an individual can adapt to shift work.
ADRB1 gene (short sleep duration)
People with certain mutations can function well on short periods of sleep.
It is less affected by sleep debt and easier to maintain concentration.
Genetic testing can help you understand your sleep characteristics and establish optimal sleep habits. For example, if you have a genetic mutation that makes you a night-owl, forcing yourself to get up early in the morning can have a negative impact on your health, so it may be advisable to adjust your work and lifestyle . ( Reference: nature.com )
⑭ The relationship between genes and cognitive function
Genetic factors also play a role in cognitive function and memory, and the risk of neurodegenerative diseases such as Alzheimer’s disease can also be predicted by genes.
Genes related to cognitive function and memory
APOE gene (risk of Alzheimer’s disease)
People with the APOE4 mutation have a 3- to 12-fold increased risk of Alzheimer’s disease.
Early brain training and dietary improvements are recommended.
BDNF gene (memory and neuroplasticity)
BDNF (brain-derived neurotrophic factor) helps form new memories.
Because the mutation increases the risk of memory decline, it is important to adopt lifestyle habits that activate the brain.
KIBRA gene (learning ability)
The mutation results in differences in short-term memory and learning ability.
If you have a genetic predisposition to poor memory, repetition and specific learning techniques can be effective.
By utilizing genetic testing, it is possible to understand the characteristics of an individual’s cognitive function and design an appropriate lifestyle to activate the brain . For example, people with APOE4 mutations are recommended to actively incorporate a diet rich in DHA (such as blue fish) and habits that stimulate the brain (reading and puzzles). (Reference: alz.org)
⑮ Optimizing beauty and skin care through genetic testing
The speed of skin aging, resistance to UV rays, and risk of wrinkles and blemishes are also determined by genes. Genetic information can be used to select skin care products that are tailored to an individual’s skin type.
Major genes related to beauty
MC1R gene (effect of UV damage)
Those with this mutation are more susceptible to damage from ultraviolet rays and more prone to developing spots.
This is a skin type for which UV protection is especially important.
COL1A1 gene (collagen breakdown)
The mutation causes collagen to break down more quickly, making wrinkles more likely to form.
Collagen supplements and vitamin C are recommended.
GSTP1 gene (antioxidant capacity)
The mutation reduces the activity of antioxidant enzymes in the body, accelerating skin aging.
Anti-aging care is possible by actively consuming antioxidant foods (blueberries and green tea).
Genetic testing can help you choose skin care products and supplements that are tailored to your individual skin type, making anti-aging measures more effective . ( Reference: ncbi.nlm.nih.gov )
⑯ Personalized fitness using genetic information
It is known that the effects of exercise and the rate at which muscles develop vary greatly from person to person, depending on genes.
Major genes that affect fitness
ACTN3 gene (fast vs. slow muscle development)
Mutations determine whether the horse is an explosive power type (suitable for short distance running) or an endurance type (suitable for marathons).
It is possible to optimize training menus to suit your genes.
PPARGC1A gene (fat burning efficiency)
The mutation determines whether aerobic exercise is more effective or not.
It serves as an indicator for choosing an efficient diet method.
IL6 gene (muscle recovery rate)
It is involved in controlling inflammation and determines how quickly muscle pain heals.
If you are genetically predisposed to slower recovery, getting adequate rest can help prevent injury.
⑰ Genetic testing and nutritional genetics: Individually optimized diet
Our diet is heavily influenced by our genes, which determine what nutrients we can absorb and metabolize efficiently. Nutrigenomics is a new science that is attracting attention as it designs optimal dietary plans based on individual genetic information .
Examples of genes that affect nutrition
MTHFR gene (folate metabolism)
If you have a mutation in the MTHFR gene, you are less likely to metabolize folic acid efficiently, which can lead to high homocysteine levels.
People with the mutation should actively consume foods rich in folic acid (green and yellow vegetables) and consider using appropriate supplements.
CYP1A2 gene (caffeine metabolism)
Due to mutations, some people break down caffeine more slowly than others.
People who have difficulty metabolizing caffeine should be careful because excessive consumption can increase the risk of insomnia and high blood pressure.
FTO gene (obesity risk)
Certain mutations in the FTO gene affect carbohydrate and lipid metabolism and increase the risk of obesity.
This type of person will benefit from a low-carb, high-protein diet.
Optimizing diet using genetic information
People at high risk of obesity → carbohydrate restriction, increased exercise
People with poor vitamin D absorption should actively consume fish and mushrooms.
People with low antioxidant enzyme activity → Increase antioxidant foods such as blueberries and green tea
With the development of nutritional genetics, it is expected that in the future, fully personalized nutritional guidance and diet programs will be provided based on genetic testing . ( Reference: ncbi.nlm.nih.gov )
⑱ Genetic information and mental health
Mental health issues are influenced not only by stressful environments and lifestyles, but also by genetic factors: Recent studies have revealed that certain genes are involved in anxiety, stress resilience, and happiness .
Key Genes Associated with Mental Health
SLC6A4 gene (serotonin transporter)
The mutation determines whether or not the plant is less tolerant to stress.
For people with low stress tolerance, exercise and mindfulness are effective.
COMT gene (dopamine metabolism)
It affects the rate at which dopamine is broken down, which is related to concentration and mood swings.
People with the mutation are more susceptible to stress and their cognitive function is more likely to be affected.
OXTR gene (oxytocin receptor)
It is involved in sociability and empathy, and influences how we build interpersonal relationships.
People with this mutation tend to be more susceptible to interpersonal stress.
Summary
Genetic testing is revolutionizing early disease detection, personalized medicine, and lifestyle optimization. It can be used for a wide range of purposes, from nutrition, sleep, mental health, beauty, and fitness. However, privacy protection and ethical issues need to be addressed. Harmony between technology and society will be the key to building a better future.
