Genetic Testing

What Is Genetic Testing?

Genetic testing, also known as DNA testing or genetic examination, is a medical process that analyzes your DNA — the unique biological blueprint that governs how your body develops and functions. By identifying changes or variants in genes, chromosomes, or proteins, genetic testing can reveal critical information about your health risks, hereditary conditions, and even how your body may respond to certain medications.

Unlike many conventional diagnostic tools that detect disease after it has already developed, genetic testing can identify inherited risks and biological predispositions at any stage of life — from before birth through adulthood. A sample as simple as a blood draw, saliva, or a cheek swab is often all that is needed to access this wealth of information.

Today, advances in technology have made genetic testing more accessible and informative than ever before from prenatal screening to hereditary cancer risk assessment.

Types of Genetic Tests

NIPT Test (Non-Invasive Prenatal Screening Test)

The NIPT test — also called the Harmony test or non-invasive prenatal screening test — is one of the most widely used prenatal genetic tools available today. It analyzes small fragments of the baby's DNA that circulate in the mother's bloodstream during pregnancy.

The NIPT/Harmony test can assess the risk of chromosomal conditions such as:

• Down syndrome (Trisomy 21)
• Trisomy 18 (Edwards syndrome)
• Trisomy 13 (Patau syndrome)
• Sex chromosome abnormalities

Because it requires only a blood draw from the mother, the NIPT test carries no risk of pregnancy loss, making it a safe and reliable first-line screening option. It is typically performed from the 10th week of pregnancy onward. It is important to note that a positive NIPT result is a screening finding — not a definitive diagnosis — and should be followed up with confirmatory diagnostic testing.

BRCA Gene Test (Breast Cancer Gene Test)

The BRCA gene test screens for mutations in the BRCA1 and BRCA2 genes — the most well-known breast cancer genes associated with hereditary cancer risk.

Individuals who carry a BRCA1 or BRCA2 mutation have a significantly elevated lifetime risk of:

• Breast cancer
• Ovarian cancer
• Prostate cancer (in men)
• Pancreatic cancer

Having a BRCA mutation does not guarantee that cancer will develop, but it does enable proactive steps — such as increased surveillance, preventive medications, or risk-reducing surgery — to be taken in consultation with your healthcare team.

BRCA gene testing is particularly recommended if you have:

• A personal or family history of breast or ovarian cancer
• Breast cancer diagnosed before age 50
• Multiple relatives affected by cancer on the same side of the family
• Ashkenazi Jewish heritage (associated with higher BRCA mutation rates)

Paternity Test

A paternity test is a DNA-based examination used to determine the biological relationship between a child and a potential father. It works by comparing specific genetic markers between individuals. Paternity testing is highly accurate (exceeding 99.9% certainty) and can be performed prenatally or after birth using a simple cheek swab or blood sample.

Genetic Methylation Test

The genetic methylation test examines chemical modifications to DNA — specifically, the addition of methyl groups to certain DNA sequences. These modifications, known as epigenetic changes, can influence how genes are expressed without altering the underlying DNA sequence. Methylation testing is used in diagnosing certain genetic disorders, some cancers, and conditions such as Angelman syndrome and Prader-Willi syndrome.

Whole Genome Sequencing

Whole genome sequencing and genome sequencing represent the most comprehensive form of genetic examination available. Rather than examining a single gene or a panel of genes, whole genome sequencing maps the entirety of a person's DNA — all 3 billion base pairs.

This approach is particularly valuable when:

• Standard genetic tests have returned negative or inconclusive results
• A genetic cause is still strongly suspected
• Rare or undiagnosed diseases are being investigated

A sample of blood, saliva, or a cheek swab is all that is needed. While the technology is complex, it is becoming increasingly available as a clinical tool and can detect genetic differences that other tests may miss.

Gene Defect Diseases: What Can Genetic Testing Detect?

Genetic testing can identify risks or confirm diagnoses for a wide range of gene defect diseases, including:

• Cystic fibrosis — a life-threatening condition affecting the lungs and digestive system
• Huntington's disease — a progressive neurological disorder
• Sickle cell anemia — a red blood cell disorder
• Phenylketonuria (PKU) — a metabolic disorder detectable through newborn screening
• Thalassemia — an inherited blood disorder affecting hemoglobin production
• Fragile X syndrome — a common cause of inherited intellectual disability

For many of these conditions, early detection through genetic testing enables timely intervention that can significantly improve quality of life.

Hereditary Cancer and Genetic Risk

Hereditary cancers account for approximately 5–10% of all cancer cases and are caused by inherited gene mutations passed down through families. Beyond BRCA1 and BRCA2, other genes associated with hereditary cancer include:

• Lynch syndrome genes (MLH1, MSH2, MSH6, PMS2) — linked to colorectal, endometrial, and other cancers
• PALB2 — associated with breast and pancreatic cancer risk
• TP53 — linked to Li-Fraumeni syndrome, a rare condition with multiple cancer risks

If there is a strong family history of cancer — particularly at a young age or across multiple generations — hereditary cancer genetic testing may be appropriate.

Understanding Your Results

Genetic test results fall into three categories:

• Positive: A relevant genetic change was detected. This does not always mean you will develop the associated condition, but it guides your healthcare team in monitoring, prevention, or treatment planning.
• Negative: No genetic change was detected. While reassuring, a negative result cannot eliminate all genetic risk, as not all disease-causing variants are currently known.
• Variant of Uncertain Significance (VUS): A genetic change was found, but its health impact is not yet fully understood. In most cases, no immediate action is required, though the classification may be updated as scientific knowledge advances.

Genetic Counseling: An Essential Step

Genetic counseling is a fundamental part of the genetic testing process — both before and after testing. A certified genetic counselor can help you:

• Determine which tests are most appropriate for your situation
• Understand what results do and do not mean for your health
• Assess the implications for your family members
• Navigate emotional and psychological aspects of genetic information
• Make informed decisions about treatment, family planning, and lifestyle

At Medical Park, our team of specialists works closely with genetic counselors to ensure that every patient receives personalized guidance throughout their genetic testing journey.

Is Genetic Testing Right for You?

Genetic testing may be beneficial if you:

• Have a personal or family history of a hereditary disease or cancer
• Are planning a pregnancy and wish to assess carrier status
• Are currently pregnant and seeking prenatal screening (NIPT/Harmony test)
• Have symptoms that suggest a possible genetic condition
• Want to understand how your genes may affect your response to certain medications (pharmacogenetic testing)

Privacy and Legal Protections

Genetic information is deeply personal. In many countries, legal frameworks exist to protect individuals from genetic discrimination in health insurance and employment. It is important to review the privacy policies of any testing provider and to understand your rights before proceeding.

Genetic Testing in Turkey at Medical Park

Turkey has become a prominent destination for advanced medical care, and genetic testing is no exception. Medical Park, Turkey's largest private hospital group, offers the full spectrum of genetic testing services — from targeted single-gene tests to whole genome sequencing — within laboratories that meet international quality standards.

Genetic Diseases departments at Medical Park specialize in the diagnosis and management of inherited and chromosomal conditions, working closely with patients and families affected by gene defect diseases to provide accurate testing, clear answers, and long-term follow-up care. Alongside this, our Medical Genetics department brings together specialists in genomic medicine and genetic counseling who guide patients through complex testing pathways — from BRCA gene testing and hereditary cancer risk assessment to prenatal evaluations such as the NIPT test and genetic methylation testing.

Together, these two departments form a comprehensive genetics service supported by oncologists, gynecologists, and other relevant specialists, ensuring that every patient receives coordinated, multidisciplinary care from consultation through to results interpretation.

For international patients, Medical Park's dedicated patient services team provides end-to-end support including appointment coordination, translation services, and travel assistance. Contact us today to learn which genetic tests are right for you and your family.