Genetic Testing: Purpose, Test Details & Results

Genetic testing is transforming healthcare by providing unprecedented insights into our DNA, allowing for earlier diagnosis, personalized risk assessment, and more targeted treatment decisions. As technology and our understanding of genetics advance, genetic tests are becoming increasingly accessible and informative—not just for rare diseases, but also for common conditions and preventive medicine. In this article, we’ll explore the purpose of genetic testing, how the tests work, and what happens after you receive your results.

Purpose of Genetic Testing

Genetic testing serves as a powerful tool that extends far beyond diagnosing rare inherited disorders. Its primary aim is to detect changes in DNA, RNA, chromosomes, or proteins that may indicate the presence, risk, or carrier status of genetic conditions. Today, genetic testing is used to clarify diagnoses, inform treatment, predict disease risk, guide family planning, and even shape lifestyle decisions. With the ability to reveal crucial information about both current health and future risks, the purpose of genetic testing is rapidly expanding in scope and utility.

Genetic Diagnosis: Pinpointing the Problem

The most traditional use of genetic testing is to confirm or exclude a diagnosis when a specific genetic disorder is suspected. For example, if a child presents with symptoms suggestive of a rare inherited disease, genetic tests can identify or rule out the causative gene mutation, guiding further medical decisions 3 5 8. This process is often critical for rare diseases, where early diagnosis can profoundly affect outcomes and treatment options.

Predictive and Risk Assessment: Looking Ahead

Genetic testing is increasingly used for predictive purposes—evaluating the risk that an individual will develop a certain disease in the future, even if they currently show no symptoms. Examples include BRCA testing for breast and ovarian cancer risk, or genetic profiling for cardiovascular disease 2 4 5 8. Predictive genetic testing can enable targeted screening, early intervention, and lifestyle modifications to reduce risk.

Carrier Testing: Family Planning and Inheritance

Carrier testing identifies individuals who carry one copy of a gene mutation that, when inherited from both parents, can result in a genetic disorder in their children. This is especially relevant for couples considering pregnancy, enabling them to make informed decisions about family planning and reproductive options 3 5 8.

Personalized Management: Tailoring Treatment

Genetic information is also used to guide medical management and treatment choices—a rapidly growing field known as pharmacogenetics. Here, genetic testing reveals how an individual’s genes affect their response to certain medications, allowing clinicians to select drugs and dosages that are most likely to be safe and effective 3 5 13.

Genetic Testing Details

Behind every genetic test is a complex process, involving a range of technologies and decision points. Understanding how genetic testing works can help demystify the process for patients and families, from the initial sample collection to test selection and interpretation.

Types of Genetic Tests

There are several categories of genetic tests, each suited to different clinical questions:

• Diagnostic Tests: Confirm or exclude a suspected condition 3 8.
• Predictive/Presymptomatic Tests: Assess risk for developing diseases later in life 4 5 8.
• Carrier Tests: Identify carriers of recessive gene mutations 3 5 8.
• Pharmacogenetic Tests: Predict response to medications 3 13.
• Prenatal and Preimplantation Tests: Detect genetic changes in embryos or fetuses 3 6.

Testing Technologies

The technology behind genetic testing has evolved rapidly:

• Cytogenetic Techniques: Used since the 1960s, these identify large chromosomal changes.
• Gene Panels: Targeted sequencing of specific genes linked to certain diseases.
• Whole-Exome Sequencing (WES): Sequences all coding regions of genes.
• Whole-Genome Sequencing (WGS): Provides the most comprehensive analysis, identifying both known and novel variants. WGS has been shown to have higher diagnostic yield compared to traditional methods, capturing variants missed by panels or WES 1.

How Tests Are Performed

• Sample Collection: Most genetic tests require a simple blood draw or saliva sample, though tissues or even cheek swabs may sometimes be used 3 7 8.
• Laboratory Analysis: DNA is extracted and analyzed using the chosen technology.
• Data Interpretation: Specialists interpret the results in the context of the patient’s medical and family history 8 13 7.

Test Selection and Counseling

Choosing the right genetic test is a nuanced process:

• Personal and Family History: A detailed history helps clinicians decide which test is most appropriate 13 8.
• Genetic Counseling: Patients should receive counseling before and after testing to understand the implications, risks, and potential outcomes 8 13. Counseling is especially critical for predictive and carrier testing, as results can impact not just the individual, but also family members.

Who Should Be Tested?

• Individuals with Symptoms: Those with signs suggesting a genetic disorder.
• At-Risk Family Members: Relatives of individuals with known genetic conditions.
• Prospective Parents: For carrier screening.
• Asymptomatic Individuals: For risk assessment of common or late-onset diseases, though this is often a personal decision requiring careful consideration 4 8.

Genetic Testing Results & Follow-Up

Receiving genetic test results can be a pivotal moment, with implications for medical care, family planning, and psychological well-being. Understanding what results mean—and what to do next—is as important as the test itself.

Types of Genetic Test Results

• Positive Result: Indicates the presence of a disease-causing mutation or risk variant. This may confirm a diagnosis, reveal carrier status, or identify increased disease risk. Follow-up may include medical management, targeted screening, preventive measures, or informing family members 5 13.

• Negative Result: No mutation found; may rule out a disorder but not always, as some genetic causes may still be undetectable with current methods. Negative results can offer reassurance, but residual risk may remain, especially in complex or multifactorial diseases 4 8 13.

• Variant of Uncertain Significance (VUS): A genetic change is detected, but its impact on health is unclear. VUS results require careful interpretation, sometimes prompting further research or testing of family members 13 10.

• Incidental/Secondary Findings: Genetic testing, particularly whole-genome sequencing, may uncover unrelated but potentially important health information. Handling of such findings varies by policy and often involves additional counseling and ethical considerations 10 13.

Communicating and Interpreting Results

• Genetic Counseling: Interpretation of results is not always straightforward. Genetic counselors play a key role in helping patients and families understand their results, the limitations of testing, and possible next steps 8 13.

• Clinical Context: Results must be integrated with clinical and family history to guide management. For example, a positive result in a gene linked to cardiovascular disease may trigger screening of relatives and early preventive care 13.

Psychological and Behavioral Impacts

• Emotional Responses: While concerns exist about negative psychological effects, studies suggest that receiving genetic risk results does not strongly impact adverse psychological outcomes. In fact, carriers may be more likely to adopt healthy behaviors after learning their risk status 11.

• Family Implications: Genetic results can have significant implications for family members, who may also be at risk. Communicating and managing these findings often requires a family-centered approach 13.

Next Steps and Ongoing Management

• Medical Action: A positive result may prompt surveillance (e.g., cancer screening), preventive treatments, or lifestyle changes 5 13.
• Further Testing: In some cases, additional genetic testing or research may be needed, especially for VUS results 13 10.
• Long-Term Follow-Up: Genetic information remains relevant throughout life, and as science advances, reinterpretation of previously identified variants may become possible 10.

Direct-to-Consumer Testing: Special Considerations

• Patient Understanding: Some individuals access genetic tests directly, without a healthcare provider. Many share results with primary care providers later, but satisfaction with follow-up varies. Actionability and clarity of results are key factors in how results are used and discussed 9.
• Counseling Still Needed: Even with direct-to-consumer testing, professional guidance is important to help interpret results and avoid misunderstandings 9 8.

Conclusion

Genetic testing is revolutionizing medicine, offering clarity, prediction, and personalization in healthcare. But it also brings complexity—from selecting the right test to interpreting ambiguous results and translating them into meaningful action. Here’s a summary of the core insights:

• Genetic testing has diverse purposes: Diagnosis, risk prediction, carrier screening, and personalized treatment 3 5 8 13.
• The testing process is multifaceted: It involves choosing the appropriate technology and test based on clinical and family history, with counseling to guide decisions 1 3 6 7 8 13.
• Results interpretation is nuanced: Positive, negative, uncertain, and incidental findings each require specific follow-up and thoughtful communication 10 13 5 8.
• Patient and family counseling is essential: Both before and after testing, to support informed decision-making and emotional well-being 8 13.
• Genetic testing’s impact is growing: It can improve medical management, motivate healthy behaviors, and influence family planning 5 11 13.
• Ongoing advances: As technology and our knowledge expand, the reach and relevance of genetic testing will only increase 1 6 7.

Whether you are considering testing for yourself, your child, or as part of planning a family, understanding the purposes, process, and implications of genetic testing is the first step toward making empowered, informed choices for your health and future.