Overview
Based on global prevalence estimates, between 42 and 71 million Africans may be living with a rare disease, yet access to genetic testing remains a significant challenge. This disparity highlights a crucial truth: understanding our genetic makeup is not just a scientific curiosity; it's a vital pathway to health, and it’s one that professionals must navigate with increasing precision.
What are DNA tests?
DNA tests, also known as genetic or gene tests, are medical tools that examine your genetic material, including genes, chromosomes, and DNA. They are designed to identify variations and changes that can confirm the presence of a genetic disease, assess the risk of developing a condition in the future, or determine if you could pass a genetic disorder to your children. These are powerful tools that offer a glimpse into your body's most fundamental instruction manual.
What are the different types of DNA tests?
DNA testing isn't a single monolithic process, but a diverse set of techniques tailored for specific purposes.
Gene testing
This is a focused approach that looks for changes in specific genes that might cause or increase the risk of a disease. It can range from a targeted single variant test to a genetic testing panel that screens for multiple conditions at once.
Genomic testing
These are large-scale tests that examine your entire DNA. Whole exome sequencing looks at the protein-coding parts of your DNA, while Whole genome sequencing analyzes nearly all of your DNA, offering the most Whole genome sequencing view currently available.
Chromosomal testing
This type of test studies chromosomes for large-scale changes, such as extra copies, missing copies, or rearrangements of segments. These changes can lead to conditions like Down syndrome.
Gene expression testing
This examines the activity level of your genes. It can be particularly useful in conditions like cancer, where certain genes may be "overexpressed" or "underexpressed."
What are DNA tests used for?
The applications of DNA testing are extensive and rapidly growing.
Prenatal testing
Performed during pregnancy to detect changes in a fetus's genes or chromosomes.
Diagnostic testing
Used to confirm or rule out a suspected genetic disorder in a person who is already showing symptoms.
Carrier screening
This test determines if a person carries a gene for an autosomal recessive disease, which could be passed on to their child.
Preimplantation testing
This is used in conjunction with in vitro fertilization (IVF) to screen embryos for genetic abnormalities before they are implanted.
Newborn screening
The most common form of genetic testing, it is required by law in the U.S. though the exact panel of conditions screened varies by state; and screens newborns for certain conditions like cystic fibrosis or sickle cell disease so that treatment can begin immediately.
Predictive and pre-symptomatic testing
These tests are performed before symptoms appear to assess a person's likelihood of developing a condition later in life.
Pharmacogenomic testing
A truly personalized approach, this test helps determine how your body might process certain medications, ensuring the most effective and safest treatment options are chosen.
What diseases can be detected through genetic testing?
Genetic testing can detect a wide range of diseases and conditions, including but not limited to:
Cystic fibrosis
Down syndrome
Familial adenomatous polyposis (FAP)
Hereditary breast cancer (BRCA1 and BRCA2 gene mutations)
Huntington's disease
Sickle cell disease
Phenylketonuria (PKU)
The tests also help determine an individual's risk for developing certain types of cancer and other complex conditions.
Test Details
How does gene testing work?
The process is generally straightforward. A healthcare provider collects a sample of your blood, hair, skin, tissue, or even amniotic fluid, and sends it to a specialized lab. There, a pathologist examines the sample for changes in your genes, chromosomes, and DNA. The results are then sent back to your provider for a detailed discussion. It's an elegant process, and the precision involved is nothing short of incredible.
What are the risks of DNA tests?
While the physical risks of most DNA tests are minimal, it's the emotional and financial aspects that can be more significant. Receiving unexpected results can trigger feelings of fear, anger, anxiety, or guilt. Furthermore, the cost of genetic testing can be substantial, and insurance coverage may vary. It's also important to remember that these tests aren't a crystal ball; they don’t provide information on all possible genetic disorders, and they are not always 100% accurate. Results may not predict the severity of a condition or when it will develop.
Results and Follow-Up
What do the results of DNA tests mean?
Test results can be categorized as positive, negative, or uncertain. A positive result indicates that a genetic change known to cause a condition has been found. A negative result means no such change was found. An uncertain result, or "variant of uncertain significance," means a genetic change was found, but there's not enough information to know if it's harmless or disease-causing. Regardless of the outcome, it's crucial to discuss the results with a healthcare professional or genetic counselor. They can help you understand the full implications and next steps.
How accurate are DNA tests?
The accuracy of a genetic test is measured by its analytical validity (can the test correctly detect a specific genetic change?) and its clinical validity (is that change truly related to the disease?). While labs recommended by genetic counselors are often regulated by federal and state standards to ensure accuracy, some direct-to-consumer companies may not follow the same rigorous regulations.
How long does it take to get the results of DNA tests?
The turnaround time for results can vary widely. Some tests may provide results in a few days, while more complex tests can take several weeks or even a month or two. Your healthcare provider will give you an accurate timeframe for your specific test.
If the results are abnormal, what are the next steps?
If a genetic test reveals an abnormal result, it's not the end of the road it’s just the beginning of a new one. The next steps will depend on the specific condition and the individual. A doctor or genetic counselor will help interpret the results and may recommend further testing, lifestyle changes, or specific treatment plans. You might also be referred to specialists or support groups to help manage the condition and its impact on your life.
Additional Common Questions
Which genetic test is best ?
There is no single "best" genetic test. The right test for you depends entirely on your personal and family medical history and what you are trying to find out. This is a question best answered by a healthcare professional or a genetic counselor who can guide you to the most appropriate test.
Can genetic test for gender be wrong ?
Yes, although it's rare. A non-invasive prenatal test (NIPT) for gender is highly accurate around 99% when performed correctly. However, an incorrect result can happen if the blood is drawn too early in the pregnancy before there is enough fetal genetic material in the mother's bloodstream.
Published 20th August 2025
References
The Cleveland Clinic, DNA Test (Genetic Testing), Available at: https://my.clevelandclinic.org/health/diagnostics/23065-dna-test--genetic-testing
African Rare Diseases Initiative (ARDI) https://globalrarediseasecommission.com/wp-content/uploads/2025/01/Care-Study-ARDI.pdf?
Mayo Clinic, Genetic testing, Available at: https://www.mayoclinic.org/tests-procedures/genetic-testing/about/pac-20384827
The Bump, Is the Ultrasound Wrong About My Baby's Gender?, Available at: https://www.thebump.com/a/ultrasound-wrong-gender