Question 1

What is WES testing?

Accepted Answer

WES (Whole Exome Sequencing) is an advanced genetic test that sequences all protein-coding regions (exons) of the human genome. Although the exome constitutes only about 1-2% of the genome, it harbors approximately 85% of known disease-causing genetic variants. WES plays a critical role in diagnosing rare genetic diseases, illuminating undiagnosed conditions, and personalized treatment planning.

Question 2

What conditions can WES detect?

Accepted Answer

WES can detect single-gene disorders (monogenic diseases), rare genetic syndromes, developmental delays, neurological disorders, hereditary cancer syndromes, metabolic diseases, and congenital anomalies. It can also be used for drug response prediction and personalized treatment selection in some cases. The test identifies pathogenic variants consistent with the clinical presentation, helping to establish a definitive diagnosis.

Question 3

Who should get WES testing?

Accepted Answer

WES is recommended for individuals with undiagnosed genetic diseases, those suspected of having rare diseases, children with developmental delays or intellectual disability, patients with multiple congenital anomalies, individuals with a family history of hereditary diseases, and patients with atypical clinical presentations. Additionally, patients who have not received a diagnosis from previous genetic tests (karyotype, microarray, gene panels) are WES candidates.

Question 4

When is WES performed?

Accepted Answer

WES is recommended when clinical evaluation and first-tier genetic tests (karyotype, CMA, targeted gene panels) fail to provide a diagnosis. It may be the first-choice test for genetically heterogeneous diseases (conditions that can be caused by multiple genes). The test can be performed at any age after symptom onset. A rapid WES option is also available for clinically urgent situations.

Question 5

How does WES work?

Accepted Answer

WES involves sequencing all exonic regions of DNA isolated from a blood or saliva sample using next-generation sequencing (NGS) technology. The resulting sequencing data is processed with bioinformatics tools, variants are identified, and classified according to ACMG (American College of Medical Genetics) criteria. Findings correlated with the clinical presentation are reported. The entire process is conducted by experienced geneticists and bioinformaticians.

Question 6

What are the benefits of WES?

Accepted Answer

WES offers the advantage of analyzing over 20,000 genes simultaneously in a single test. This provides significant time and cost savings compared to traditional sequential testing approaches. It yields a high diagnostic rate (~25-40%) for undiagnosed diseases. Additionally, it forms the basis for personalized treatment (precision medicine) approaches and provides valuable information for genetic counseling in family planning.

Question 7

Can WES detect all genetic conditions?

Accepted Answer

WES covers approximately 85% of known disease-causing variants. However, it has limitations: it does not fully analyze non-exonic (intronic/regulatory) regions, cannot reliably detect large deletions/insertions or repeat sequences, and does not cover triplet repeat diseases or epigenetic changes. In these cases, WGS (Whole Genome Sequencing), MLPA, or other targeted testing may be required.

Question 8

How accurate is WES?

Accepted Answer

WES provides high accuracy (>99% base calling accuracy) in exonic regions. However, like any test, some variants may be missed due to technical limitations. The detection rate of clinically significant variants depends on test quality, bioinformatics pipeline robustness, and clinical information accuracy. Omega Genetik delivers the most reliable results with ACMG-compliant classification and clinical correlation.

Question 9

Are there risks with WES testing?

Accepted Answer

WES is a non-invasive test performed with blood or saliva samples and carries no physical risk. However, unexpected findings (incidental findings) may arise — for example, an asymptomatic hereditary disease susceptibility may be identified. These situations should be managed through genetic counseling. Ethical and psychological assessment is important.

Question 10

How long does WES testing take?

Accepted Answer

WES results are typically available within 4-6 weeks. In urgent clinical situations, accelerated processing (rapid WES) can deliver results in 7-14 days. The timeline may vary depending on sample quality, laboratory workload, and case complexity. When results are ready, our patient representative will inform you and the report will be sent to your physician.

Question 11

What is the WES procedure?

Accepted Answer

The WES procedure includes the following steps: (1) Physician referral and collection of clinical information, (2) Blood (EDTA tube, 4-6 ml) or saliva sample collection, (3) DNA isolation and exome enrichment (capture), (4) Sequencing on NGS platform, (5) Bioinformatics analysis and variant classification, (6) Clinical correlation and reporting. Omega Genetik's experienced team meticulously manages each step.

Question 12

How are WES results interpreted?

Accepted Answer

WES results are classified according to ACMG criteria: Pathogenic (P), Likely pathogenic (LP), Variant of uncertain significance (VUS), Likely benign (LB), and Benign (B). The report includes pathogenic/likely pathogenic variants correlated with the clinical presentation. Variant interpretation considers clinical findings and family history. Genetic counseling is strongly recommended for proper understanding of results.

Question 13

What happens if a VUS (variant of uncertain significance) is found?

Accepted Answer

Variants of uncertain significance (VUS) are variants where current scientific data is insufficient to determine whether they cause disease. VUS findings are periodically reclassified in light of new scientific data. Classification may change when new data is published or functional studies are completed. Omega Genetik offers VUS follow-up and reclassification services.

Question 14

What does a negative result mean?

Accepted Answer

A negative result means no pathogenic variants consistent with the clinical presentation were found in the tested exonic regions. This does not definitively rule out a genetic cause. With a negative result, the following options may be considered: WGS (whole genome sequencing), RNA sequencing, clinical follow-up, and re-analysis. As scientific literature advances, re-analysis of previous WES data may yield new diagnoses.

Question 15

What is Trio WES and why is it recommended?

Accepted Answer

Trio WES includes WES testing of both parents along with the patient. This approach is much more powerful for identifying de novo variants, tracking the origin of inherited variants, and improving clinical interpretation of VUS. Trio analysis significantly increases diagnostic yield and is especially recommended for pediatric patients and rare disease diagnosis.

Question 16

Do my family members need to be tested?

Accepted Answer

In some cases, checking whether a variant found in one family member is also present in other family members (segregation analysis) may be necessary. This is important to confirm the variant's association with the disease. Additionally, family member testing may be recommended to determine carrier status in suspected familial hereditary diseases.

Question 17

Can WES be used for carrier screening?

Accepted Answer

Yes, WES can perform carrier screening for autosomal recessive and X-linked diseases. However, WES is primarily designed for diagnosing patients with clinical symptoms. For standard carrier screening, specific panel tests may be more appropriate. Genetic counseling is recommended before family planning for couples.

Question 18

How is a sample provided for the test?

Accepted Answer

For WES testing, a blood sample (in EDTA tube, 4-6 ml) or saliva sample can be used. No fasting or special preparation is required for blood collection. A special kit is used for saliva samples. The sample is securely transported to Omega Genetik laboratory. With our at-home blood draw service, our licensed nurse comes to your designated address.

Question 19

Is special preparation needed before WES?

Accepted Answer

No, WES testing does not require fasting, medication discontinuation, or special preparation. Blood can be drawn at any time. However, it is important that your physician's clinical information (symptoms, history, family tree) is fully shared before the test. This information plays a critical role in the analysis and interpretation process.

Question 20

Is there an at-home blood draw service?

Accepted Answer

Yes, through the Omega Care Home Health team, we offer at-home blood draw service across Türkiye. Our licensed nurses come to your address at the date and time you specify to professionally collect blood samples. The sample is transported to our laboratory according to safe transport standards. This service is especially ideal for patients with mobility issues and children.

Question 21

Is WES testing covered by insurance?

Accepted Answer

Some comprehensive private health insurance plans may cover WES testing. Government insurance (SGK) may provide partial coverage for specific indications. You can check your coverage by contacting your insurance provider. Omega Genetik patient representatives assist you with the insurance process.

Question 22

What is the cost of WES testing?

Accepted Answer

The cost of WES testing varies depending on the test type (standard/trio), speed (standard/rapid), and scope. For current pricing information, you can fill out our appointment form or contact our patient representatives. Payment options include credit card, debit card, and installment plans.

Question 23

What should I consider before getting WES?

Accepted Answer

Before WES, it is important to have physician referral, clear documentation of the clinical presentation, family history mapping, and genetic counseling. You should be informed about potential test outcomes (pathogenic findings, VUS, incidental findings). Also consider post-test follow-up and re-analysis options.

Question 24

Where are results processed?

Accepted Answer

WES test results are processed at Omega Genetik Laboratory, which is licensed and approved by the Ministry of Health. Our laboratory uses the latest NGS platforms and accredited bioinformatics infrastructure. We operate in compliance with all national and international quality standards (ISO, CAP). Processes managed by experienced geneticists and bioinformaticians ensure the most accurate and reliable results.

Question 25

How is my data and privacy protected?

Accepted Answer

Patient data and genetic information are protected at the highest level under the KVKK (Personal Data Protection Law) and relevant health regulations. All data is stored in encrypted systems, protected against unauthorized access. Data may only be used for research purposes with patient consent. Our laboratory holds data security certifications.

Question 26

Is physician referral required for WES?

Accepted Answer

Yes, WES testing requires a referral from a relevant specialist physician (medical genetics, pediatric neurology, pediatrics, internal medicine, etc.) and a clinical information form. The clinical information provided by your physician (symptoms, history, previous test results) is critical for proper analysis and interpretation of the test. Testing is not performed without physician referral.

Question 27

What is the difference between WES and WGS?

Accepted Answer

WES (Whole Exome Sequencing) analyzes only protein-coding regions (~1-2% of the genome), while WGS (Whole Genome Sequencing) analyzes the entire genome (~3 billion bases). WES is more cost-effective, faster to interpret, and covers the vast majority of disease-causing variants in the exome. WGS also analyzes non-exonic regulatory regions, providing more comprehensive information but at higher cost and with greater data interpretation challenges.

Question 28

How does WES differ from karyotype and CMA?

Accepted Answer

Karyotype detects large chromosomal abnormalities (trisomy, translocation, etc.); CMA (Chromosomal Microarray Analysis) detects submicroscopic deletions/duplications (CNVs). WES detects nucleotide-level variants ranging from single base changes (SNVs) to small insertions/deletions. These tests are complementary; which to apply depends on the clinical presentation. WES has the highest diagnostic value when karyotype and CMA are insufficient.

Question 29

How do WES results affect treatment choices?

Accepted Answer

WES enables precision medicine by establishing a definitive diagnosis through identification of pathogenic variants. For example, dietary therapy for certain metabolic diseases, targeted therapy for specific cancer syndromes, or repurposed drug use may be possible. Additionally, opportunities for clinical trial participation may arise. WES results should be evaluated together with your physician.

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