Genetic testing has become an essential tool in healthcare and research, offering critical insights into an individual’s genetic predispositions, medication response, and potential hereditary traits. With advancements in genomics, personalized medicine is rapidly reshaping healthcare, making it increasingly important to understand your genetic profile for informed decision-making.
However, the growing number of available genetic tests can be overwhelming. These tests, which assess different aspects of genetic health, require careful evaluation to determine the most relevant approach based on individual needs and health goals.
In this article, we will explore the various types of genetic tests, their scientific basis, and how they contribute to more precise, personalized healthcare strategies.
Importance of Genetic Testing
Genetic testing enables early disease detection and prevention by identifying genetic risks before symptoms arise, empowering individuals to make proactive health decisions and improve long-term outcomes.
Early Detection and Prevention
Genetic testing supports early detection and proactive measures, such as screenings and lifestyle changes, to reduce the risk of conditions like cancer, heart disease, and neurological disorders.
For example, Christina Applegate, a popular American actress, was diagnosed with breast cancer in 2008. She underwent a double mastectomy and later took additional steps to reduce her cancer risk by having her ovaries and fallopian tubes removed. She carries the BRCA1 gene mutation, which significantly increases the likelihood of developing both breast and ovarian cancer.
This decision is a direct example of how individuals with BRCA1 and BRCA2 mutations can take preventive measures such as oophorectomy (removal of ovaries and fallopian tubes) to reduce their cancer risks drastically. While this surgery doesn’t eliminate the risk, it can lower ovarian cancer risk by up to 96% and breast cancer by up to 50%, offering a critical form of risk management for those affected.
Personalized Medicine
Genetic testing enables tailored treatments by understanding how genes influence drug responses and disease susceptibility, leading to more effective healthcare plans.
Recently, Illumina announced the launch of the MiSeq i100 Sequencer, a compact and affordable next-generation sequencing (NGS) platform. This device offers affordable, high-quality genomic sequencing with a fast 4-hour turnaround. Priced at $49,000, it processes up to 1.5 gigabases of data, enabling timely, cost-effective testing in smaller labs and clinical settings.
Geneviève DonPierre of Génome Québec highlighted its ability to quickly deliver answers for small projects, while Tim Roloff Handschin at the University of Zurich praised the 24-hour bacterial culture turnaround and increased sample throughput, enhancing flexibility and accelerating test development. This technology supports personalized medicine by tailoring treatments based on genetic data, improving drug efficacy, and reducing side effects.
Informed Family Planning
Genetic screening for inherited conditions (e.g., cystic fibrosis, sickle cell anemia) allows couples to make informed reproductive choices, reducing the risk of genetic disorders in future generations.
Recently, the NHS has launched the Generation Study, a pioneering initiative to test newborns for over 200 treatable rare genetic conditions using whole genome sequencing. This study aims to screen up to 100,000 babies, identifying treatable conditions like metachromatic leukodystrophy (MLD) early, allowing for timely intervention that can improve or extend lives.
The study, led by Genomics England and NHS England, involves taking blood samples from newborns and analyzing their DNA to detect conditions that may not show symptoms until later in childhood.
Utility of Genetic Tests to Determine Autosomal Dominant Inheritance
Types of Genetic Testing
Genetic testing can identify changes in genes, chromosomes, or proteins, helping confirm or rule out genetic disorders. Below are some of the most common types of genetic tests and how they contribute to healthcare.
Targeted to Comprehensive Genetic Tests
Genetic testing can range from targeted tests that focus on specific genes or conditions to comprehensive tests that analyze the entire genome for a broader range of potential issues.
1. Single Gene Testing
Single-gene tests focus on identifying mutations in one specific gene associated with a particular condition. These tests are used when a known genetic disorder is linked to a specific mutation.
- What It Measures
- Single gene tests examine one gene for mutations or variants associated with a specific disease.
- When It’s Used
- This test is ideal for confirming or ruling out a diagnosis, particularly when a known condition is associated with a specific gene variant. It is especially useful when multiple mutations in one gene can lead to the suspected condition.
- Example: Familial Conditions
- Used to test family members of someone with a known genetic variant.
- Helps determine if relatives carry the same mutation and are at risk for the same condition.
- Benefits
- Single gene testing provides a precise, focused analysis, making it more cost-effective and accurate for diagnosing conditions linked to specific genetic markers.
2. Genetic Testing Panels
Genetic testing panels analyze multiple genes to identify variants that may contribute to a specific condition or set of symptoms.
- What It Measures:
- These tests screen multiple genes involved in a condition or health issue.
- When It’s Used:
- Genetic panels are helpful when symptoms match a broad range of conditions or when the suspected disease could be linked to multiple genetic factors.
- Example: Epilepsy
- With hundreds of known genetic causes of epilepsy, a panel test can quickly screen all relevant genes, expediting diagnosis and treatment.
- Benefits:
- Provides a more comprehensive analysis of genes related to a specific health issue.
- Often quicker and more cost-effective than conducting multiple single-gene tests.
3. Whole Genome and Exome Sequencing
Whole genome sequencing (WGS) and exome sequencing (WES) extensively analyze an individual’s DNA.
- What They Measure:
- Exome Sequencing (WES) focuses on the exons—regions of DNA that code for proteins.
- Whole Genome Sequencing (WGS) examines both coding and non-coding regions of DNA, including regulatory regions that control gene activity.
- When to Use These Tests:
- These tests are used when single-gene tests or panels fail to provide a diagnosis or when the suspected genetic condition is unclear.
- Benefits:
- Exome sequencing is effective in detecting known genetic disorders, while WGS offers a more comprehensive approach by examining nearly all of an individual’s DNA. These tests provide valuable insights when simpler tests do not yield answers.
Advanced Genetic Testing
1. Chromosomal Tests
Chromosomal tests examine the structure, number, and arrangement of chromosomes to detect genetic conditions.
- What It Measures:
- These tests examine whole chromosomes or large sections of DNA to detect significant genetic changes.
- They can identify abnormalities in the number or structure of chromosomes.
- Karyotyping:
- A common method used in chromosomal testing.
- It visually represents all chromosomes, making it easier to spot abnormalities, such as an extra or missing chromosome.
- Detecting Chromosomal Disorders:
- Down syndrome: A condition caused by an extra copy of chromosome 21, which can be identified through chromosomal testing.
- Abnormalities can also involve parts of chromosomes being missing, duplicated, or translocated (moved to a different chromosome).
- Types of Abnormalities Detected:
- Chromosomal tests can detect deletions (missing sections) as small as 3-5 Megabase (Mb) and duplications larger than 5 Megabase (Mb).
- Structural changes, such as parts of chromosomes rearranged, can also be identified.
- Clinical Role:
- Chromosomal tests are critical for diagnosing conditions such as Down syndrome, where an extra copy of chromosome 21 is present, or other genetic disorders caused by chromosomal abnormalities.
2. Biochemical Tests
Biochemical tests help understand how genetic variations affect the body’s metabolic processes. Biochemical tests measure enzyme or protein activity to assess the metabolic impact of genetic mutations.
- What It Measures
- Rather than directly analyzing DNA, biochemical tests measure how genetic variations affect protein function and metabolic processes.
- Applications
- These tests are key in diagnosing Inborn Errors of Metabolism (IEM)—genetic disorders that affect how the body processes food and waste.
- In disorders like phenylketonuria (PKU), a biochemical test can detect the levels of phenylalanine (a type of amino acid) in the blood, helping to diagnose the condition early.
- Biochemical tests are crucial in diagnosing Gaucher disease or Tay-Sachs, where enzyme deficiencies can cause severe complications if untreated.
- Biochemical Genetics Laboratories offer specialized testing to assess inherited genetic disorders.
3. Gene Expression Tests
Gene expression tests assess how genes are activated or suppressed in cells, providing insights into how genetic changes impact health.
- What it Measures:
- These tests measure RNA levels, reflecting gene activity and protein production.
- Applications in Cancer:
- Gene expression tests are used in cancer treatment, such as evaluating gene expression in breast cancer to guide decisions about chemotherapy.
- Autoimmune and Inflammatory Diseases:
- Gene expression tests can assess how immune system-related genes are expressed in autoimmune conditions, helping to determine the disease’s activity and severity.
- This allows for more targeted treatment options based on how the immune system is functioning.
- Why It Matters:
- Provides real-time insight into how genes are influencing health.
- Helps doctors personalize treatments based on individual gene activity.
- Offers more accurate predictions for disease progression or response to treatment.
Gene expression tests give a clearer picture of genetic activity, making them essential for understanding complex health conditions and developing tailored treatment plans.
Now that we’ve explored various genetic tests, let’s move on to the applications of genetic testing in health.
Applications of Genetic Testing in Health
Genetic testing personalizes healthcare by customizing treatments and lifestyle choices based on an individual’s genetic profile, ensuring more effective interventions and reducing adverse side effects.
Pharmacogenomics
Pharmacogenomics analyzes how genes affect drug responses, allowing for personalized medication prescriptions and dosage adjustments. This improves treatment efficacy and minimizes side effects.
For example, genetic variants in LDLR, APOB, and PCSK9 impact LDL cholesterol (LDL-C) levels and cardiovascular risk. Loss-of-function mutations in PCSK9, for example, naturally lower LDL-C, leading to the development of PCSK9 inhibitors for targeted lipid-lowering therapy.
Recently, AstraZeneca has signed a $1.92 billion deal with CSPC Pharmaceutical Group to develop a novel Lipoprotein(a) disruptor aimed at treating high cholesterol (Lp(a)) linked to cardiovascular diseases. The deal includes an upfront payment of $100 million and milestone royalties, with AstraZeneca integrating this new therapy with its existing treatments for enhanced lipid-lowering solutions.
Optimized Lifestyle Choices
Genetic testing tailors lifestyle decisions, such as diet and exercise, to an individual’s genetic makeup. It can guide diet plans based on fat metabolism and design exercise routines suited to personal health risks, leading to more effective, sustainable health management.
A Holistic Approach to Health Management
By combining personalized treatments with optimized lifestyle strategies, genetic testing empowers individuals to manage health risks more effectively, improving long-term outcomes and overall well-being.
Conclusion
Genetic testing offers a powerful lens to better understand health risks, treatment options, and family planning decisions. From identifying genetic predispositions to personalizing treatment plans, genetic testing is reshaping modern healthcare. As genomics research progresses, the potential applications of genetic testing continue to expand.
At Biostate AI, we provide innovative Total RNA Sequencing technology, empowering researchers to explore genetic complexities with greater precision. We enable detailed studies across diverse biological samples with scalable solutions and cost-effective pricing.
Request a personalized quote today and leverage our expertise to drive forward your research.