MOLECULAR GENETICS

NGS

POC/CVS/AF/FOETUS SAMPLE & MOTHER WB EDTA

* Fasting: No fasting is required for the pregnant mother or for the collection of fetal/POC samples. You can eat and drink normally. *
* Medications/Supplements: * Generally, routine medications and supplements do not interfere with DNA analysis. However, it is advisable for the pregnant mother to inform her doctor and the lab about ALL current medications and supplements, especially those that might affect fetal development or the medical indication for the test. *
* Clinical History Required (Absolutely Crucial): Providing detailed and accurate clinical information is paramount for the successful interpretation of the extensive genetic data generated. This information guides the geneticists and bioinformaticians in prioritizing and interpreting identified genetic variants relevant to the fetal condition. * Detailed Fetal Phenotype/Anomalies: Comprehensive ultrasound findings (e.g., type and severity of structural anomalies, hydrops, growth restriction), MRI findings, and any other relevant clinical observations. For post-loss cases, detailed autopsy findings are essential. *
* Reason for Testing: Clearly state the precise medical indication for the test (e.g., abnormal ultrasound, suspected genetic syndrome, family history, recurrent pregnancy loss with previous abnormal fetuses, diagnosis after termination). *
* Family History: A detailed family pedigree for both prospective parents, including information on any relatives with similar symptoms, known genetic conditions, previous miscarriages, stillbirths, or consanguinity (blood relationship between parents). This helps in understanding potential inheritance patterns. *
* Previous Genetic Test Results: Provide results of any prior chromosomal microarray, karyotype, targeted gene panels, or biochemical tests performed on the fetus or parents. This avoids redundant testing and helps focus the analysis. *
* Parental Information: Clinical information for both biological parents, especially if they have any health conditions or are known carriers of genetic variants. *
* Genetic Counseling (Highly Recommended and Often Required): * Pre-test genetic counseling with a qualified genetic counselor or medical geneticist is strongly recommended and often a mandatory step due to the complexity and implications of this test. *
* Reason: They can explain the comprehensive nature of this test, its benefits, limitations, potential outcomes (including variants of uncertain significance - VUS, and incidental findings), the critical role and implications of MCC, the unique challenges of prenatal/fetal genetic testing, implications for future pregnancies, and help ensure truly informed consent. *
* Informed Consent: * Due to the profound complexity, sensitivity, and familial implications of prenatal genetic testing, detailed informed consent is required from the pregnant mother (and often the father). This typically covers what will be analyzed, how results will be interpreted, data privacy, and policies regarding secondary/incidental findings. *
* Sample Collection Expertise & Timeliness: * The collection of fetal samples (CVS, AF, POC) requires specialized medical procedures performed by experienced clinicians to minimize risks and ensure optimal sample quality and quantity. Proper handling, storage, and timely transport of the sample to the lab are crucial to maintain DNA integrity. For POC samples, collection immediately after miscarriage/termination and proper preservation are vital.

What is Whole Exome Sequencing (WES)?

WES is a next-generation sequencing method that analyzes all protein-coding regions (exons) of the genome, covering approximately 1-2% of total DNA but containing about 85% of known disease-causing mutations.

Why is MCC testing important in prenatal WES?

Maternal Cell Contamination occurs when maternal DNA mixes with the fetal sample (POC/CVS/amniotic fluid). MCC testing quantifies this contamination to ensure detected variants are truly fetal and not maternal in origin.

What samples are accepted for this test?

This test accepts chorionic villus sampling (CVS), amniotic fluid (AF), products of conception (POC), fetal tissue, along with maternal whole blood in EDTA tube for MCC comparison.

How long does WES reporting take?

Turnaround time is typically 15-21 working days depending on sample quality, sequencing depth, and variant filtering complexity.

What conditions can WES detect in prenatal samples?

WES can identify variants associated with monogenic disorders, congenital anomalies, skeletal dysplasias, metabolic disorders, and neurodevelopmental conditions with high genetic suspicion.

Do I need to fast before sample collection?

Fasting is not required for WES sample collection. The procedure depends on the prenatal sampling method (CVS/AF/POC) performed by your clinician.