What are DNA Tests?

DNA tests, also known as genetic tests, are medical procedures used to identify mutations in genes, chromosomes, or proteins. These mutations can indicate the presence of genetic conditions, assess the risk of developing certain diseases, or determine the likelihood of passing genetic traits to offspring. These tests analyze different aspects of genetic material:

• Genetic tests focus on individual genes or groups of genes to identify mutations that could be linked to genetic disorders. These tests can analyze a single gene, several genes, or the entire genome to assess the risk of genetic diseases.
• Chromosomal tests evaluate the structure of chromosomes, which are long strands of DNA, to identify any significant alterations that may lead to genetic conditions. This includes identifying any abnormal number of chromosomes, such as extra copies, which can cause genetic disorders.
• Protein tests measure the activity of enzymes in cells, detecting the byproducts of chemical reactions. These byproducts can provide evidence of DNA changes associated with genetic disorders. Issues detected in protein function can indicate genetic conditions resulting from DNA mutations.

What DNA tests can tell you about your health?  

Genetic testing plays an important role in understanding the complexities of various human diseases by investigating inherited genetic mutations and their interplay with environmental factors. These tests provide insights into an individual's genetic composition, allowing for the identification of potential health risks and enabling early prevention or intervention. Here's what DNA tests can reveal about your health:

1. Genetic Predispositions: DNA tests can identify mutations or variations in your genes that may increase your risk for certain diseases, such as heart disease, cancer, Alzheimer's disease, and diabetes.

2. Carrier Status: They can show whether you carry a gene variant that could be passed on to your children, leading to inherited conditions like cystic fibrosis, sickle cell anaemia, and Tay-Sachs disease.

3. Pharmacogenetics: Some tests provide insights into how your body might metabolise or react to certain medications, which can help in tailoring treatments to your genetic makeup for more effective healthcare.

4. Nutrigenomics: DNA tests can offer information on how your genetics might influence your body's response to certain nutrients and diets, aiding in personalized nutrition plans for better health outcomes.

5. Ancestry and Traits: While not directly related to disease, some DNA tests can provide information about your ancestry and inherited traits, such as lactose intolerance, caffeine metabolism, and even aspects of physical appearance.

6. Wellness Insights: Certain tests can give you insights into aspects of your wellness that may have a genetic component, such as sleep patterns, weight predispositions, and muscle composition.

7. Disease Risk Assessment: Some advanced DNA tests can assess your risk for complex diseases such as cancer, cardiovascular disease (CVD), diabetes, as well as autoimmune disorders, that involve multiple genes and environmental factors, providing a more comprehensive health outlook.

8. Early Detection and Prevention: In some cases, DNA tests can detect early signs of diseases, such as vision loss, obesity, cardiovascular disorders, etc., enabling proactive measures and preventive healthcare strategies to mitigate risks.

It's important to note that while DNA tests can provide valuable information about your health, they are not definitive predictors of disease. Environmental factors, lifestyle choices, and family history also play significant roles in your overall health.

Types of DNA tests and their significance in Health and Ageing

Different DNA testing methods are instrumental in decoding aspects of health and the ageing process. Blood tests, which isolate DNA from white blood cells, shed light on one's biological age and the effects of lifestyle choices. Saliva tests, known for their non-invasive nature, assess DNA methylation patterns to gauge biological age and general health. Additionally, microbiome tests, which examine the DNA of gut microorganisms, enhance our comprehension of ageing and strategies for disease prevention. Collectively, these testing techniques are invaluable for evaluating biological age and advocating for practices that support healthy ageing.

Blood Test

Blood-based biomarkers are essential for understanding healthy ageing and tracking the progression of age-related diseases. Geroscience, a field of biological ageing studies, integrates ageing research with clinical applications to identify key biomarkers. DNA methylation, an epigenetic change affecting gene expression, serves as a critical marker, acting as a "molecular clock" that aligns with chronological age. This epigenetic alteration involves changes in the methylation of cytosine bases within DNA, affecting gene expression and potentially contributing to premature ageing and cancer development. Telomere length is another key ageing biomarker because telomeres shorten as we age, and rapid shortening is linked to age-related diseases.

In addition to DNA biomarkers, a panel of experts identified a shortlist of promising blood-based biomarkers, including inflammatory markers like IL-6, TNFα-receptor I or II, CRP, and GDF15; metabolic markers like insulin levels, metabolic markers like IGF1, cystatin C, NT-proBNP and haemoglobin A1c; and cellular senescence markers such as senescence-associated secretory phenotype (SASP), highlighting their potential in predicting mortality, clinical, and functional outcomes, and their responsiveness to interventions. These tests uncover details about nutrient levels, inflammation, metabolic and cellular health, and also detect nutrient deficiencies, paving the way for targeted interventions to enhance a healthy lifespan​.

Gut Microbiome test

Microbiome testing is a non-invasive method that analyses the DNA of the microorganisms living in the gut - including bacteria, fungi, viruses, and other microbes. This technique utilises the stool sample of the individual, which is then dispatched to a laboratory for DNA examination. The laboratory sequences the DNA of the microorganisms found in the sample, comparing it with a reference database to pinpoint the specific types of microbes present in the gut.

The primary goal of microbiome testing is to uncover the composition and diversity of the gut microbiome, which influences overall health. This type of testing can identify various diseases such as Irritable Bowel Syndrome, Irritable Bowel Diseases, systemic metabolic disorders like obesity and diabetes, as well as Atopic Eczema and other allergic conditions.

Furthermore, scientific research suggests that the gut microbiome plays a crucial role in the ageing process. The connection between the gut microbial ecosystem and the health status of older adults suggests that alterations in the gut microbiome composition could be a viable strategy to promote healthy ageing, potentially mitigating age-related health issues and enhancing life quality in later years.

Saliva test

Saliva is emerging as a promising medium for biomarker testing, including the determination of biological age. Research has primarily focused on various DNA biomarkers present in saliva, such as DNA methylation, telomere length, cell-free DNA, and circulating tumour DNA, with a particular emphasis on DNA methylation studies. This research has expanded beyond cancer to include investigating the impact of environmental and lifestyle factors on saliva DNA methylation patterns, such as exposure to air pollution and smoking. Saliva also offers insights into cellular ageing through telomere length. Studies have demonstrated variations in telomere length associated with health status and lifestyle factors.

Moreover, saliva contains a range of inflammatory biomarkers, including IL-18, IL-2, IL-17, IL-12, and CRP, which are associated with chronic diseases and the ageing process itself. These biomarkers can indicate systemic inflammation levels, offering critical insights into aging-related pathologies. Notably, the correlation between salivary and blood biomarkers, particularly for inflammatory markers like IL-6, underscores the potential of saliva as a non-invasive alternative to blood for diagnostic purposes.

Salivary biomarkers have been utilised in the diagnosis and monitoring of various diseases, including cortisol for stress disorders, C-reactive protein (CRP), creatine kinase isoform MB, and myoglobin for cardiovascular disease, pathogens, nucleic acids, and antibodies for infectious processes, α-2-macroglobulin and glycosylated haemoglobin (HbA1c) for diabetes, and various interleukins (ILs) for cancers, gastrointestinal disorders, and muscle or joint disorders. Advances in saliva collection and analysis methodologies are enhancing its reliability and accuracy for detecting biomarkers. This progress is making saliva an increasingly attractive option for biological age testing and monitoring of health and disease progression.

DNA Tests available in India

In India, a range of DNA tests cater to diverse needs, the health-related DNA tests provide valuable insights into genetic predispositions for various conditions, empowering individuals to make informed lifestyle choices and proactive healthcare decisions. 

Decode Age BioAge

BioAge test uses epigenetic markers to gauge an individual's biological age, offering a comprehensive assessment that includes eye, hearing, memory age, and inflammation levels, along with customised improvement suggestions. It validates the impact of personal biohacks and interventions, aiding in precise healthy ageing and enhancing health strategies. Despite its affordability, it stands out for delivering quick, tangible outcomes in a field with few alternatives.

Sample: Saliva Sample
Testing time: 4-7 weeks

Key Advantages:

• Consultation: Personalised Health Recommendations from Genetic Experts
• Progress Tracking: Regular Epigenetic Retesting Options
• Detailed Reports: Biological Age, Memory Age, Hearing Age, Eye Age, etc.
• Special Feature: Optimal diet, lifestyle, and supplement recommendations based on genetic predispositions.

Decode Age Biome

Decode Biome offers a leading gut microbiome test kit in India, leveraging advanced shotgun sequencing technology to analyze the complex balance of microbes in the gut. This cost-effective solution provides personalized insights, enabling users to improve digestion, boost immunity, manage weight, and enhance overall health, delivering quick and tangible results.

Sample: Stool Sample
Testing time: 3-4 weeks

Key Advantages:

• 20+ Gut Health Scores
• Disease Risk Assessment
• Microbiome Profiling - Good and Bad Bacteria
• Personalised Probiotic Recommendations
• Personalised Food Recommendations
• Free Consultation with a Nutritionist

Conclusion

DNA tests are crucial in modern healthcare, providing critical insights into genetic predispositions, potential disease risks, and tailored health advice. These tests, which include genetic, chromosomal, and protein assessments, offer invaluable data for disease prevention and personalized health management. They empower individuals to proactively manage their health through customized lifestyle changes and early intervention measures. Additionally, technological advancements in DNA testing have enhanced their accessibility and convenience, including at-home testing options, making DNA tests a key component in fostering comprehensive health and wellness.

FAQs:

1) Why do people need DNA testing?

A DNA test is a medical examination designed to identify mutations in genes, chromosomes, or proteins. These mutations can indicate the presence or absence of genetic conditions, and the test also evaluates the likelihood of developing certain conditions or passing on genetic disorders. This diagnostic procedure helps individuals comprehend their genetic predispositions and potential health prospects.

2) What is the purpose of the DNA test?

DNA testing aims to reveal significant details about an individual's genetic composition. These examinations offer insights into ancestry, health issues, and possible genetic attributes. Through DNA analysis, people gain knowledge about their lineage, identify their susceptibility to specific illnesses, and biological age, and make educated choices regarding their well-being and lifestyle. Ultimately, DNA testing enables individuals to proactively enhance their health and quality of life by utilising personalised genetic data.

3) Can a DNA test tell your age?

Although a DNA test cannot directly disclose one's chronological age, it can offer indications of biological age by analyzing specific genetic markers associated with ageing, such as telomere length and DNA methylation patterns. This estimation provides insights into overall health and potential age-related conditions.

4) Can you be biologically younger than your age?

Yes, it's achievable to have a biological age younger than your chronological age. Lifestyle modifications like embracing a nutritious diet, consistent physical activity, sufficient sleep, stress reduction techniques, etc., have the potential to reverse biological age. These changes aid in decelerating the ageing process and enhancing overall health.

5) What are the advantages and disadvantages of DNA tests?

Advantages of DNA tests include providing self-awareness, insights into potential genetic diseases, and personalized health information. They offer tailored lifestyle recommendations for proactive health management, all accessible through convenient home testing without the need for healthcare provider approval. On the other hand, DNA tests have limitations. While they reveal risk levels for specific conditions, they cannot definitively predict outcomes.

 

References

1. https://www.indushealthplus.com/genetic-dna-testing/which-diseases-are-detected-by-dna-tests.html 
2. https://www.igenomix.co.in/our-blog/what-diseases-can-be-detected-through-genetic-testing/ 
3. https://www.medicalnewstoday.com/articles/how-might-bacteria-eating-viruses-and-gut-bacteria-contribute-to-longevity#Implications-for-future-research 
4. http://mortalitypredictors.org/