The GeneScreen® test
GeneScreen® is an advanced carrier screening test that identify couples who are at risk of passing inherited disorders to their children.
Expectant parents, or couples planning a family, may be at risk for passing on severe genetic diseases to their offspring. If both parents are carriers for an autosomal recessive or X-linked condition they have a 1 in 4, or 25%, chance of having an affected child.
The GeneScreen® Carrier Screening test provides a closer look at genes, to see if the couple is at risk of passing a hereditary genetic disorder to their offspring.
The GeneScreen® test screens for the most clinically relevant and impactful genetic conditions that typically affect health in infancy or childhood. The disorders included in the GeneScreen® test panel have been carefully selected for preconception and prenatal carrier testing. Each condition is selected based on carrier rate, clinical severity, and availability of treatment options. These disorders can cause serious health problems, intellectual disability, or a shorter life. Testing can be performed before conception, or at any time during pregnancy.
GeneScreen® Carrier Screening test screens severe diseases according to the guidelines of the European Society of Human Genetics (ESHG), including those recommended by prestigious international societies, such as the American College of Medical Genetics and Genomics (ACMG) and the American College of Obstetricians and Gynecologists (ACOG)
GeneScreen®: Indications for testing
GeneScreen® carrier screening test is intended for patients who meet any of the following criteria:
• Individuals with a family history of a genetic disease, who are therefore at higher risk of being carriers for those diseases
• Individual belonging to certain ethnicities with high risk of being carriers of hereditary recessive disorders.
• For patients who are pursuing pregnancy with assisted reproductive technologies.
• Couples planning to start a family or to extend it, and willing to know if they are carriers of monogenic recessive diseases that can be transmitted to their offspring, in order to make more informed reproductive decisions.
• Couples requiring gamete donation, in order to select the most appropriate donor for each recipient (i.e. a donor that doesn’t carry the same mutation as the member of the couple who will provide the gametes), minimizing the reproductive risk.
• Gamete banks or IVF clinics to analyze every egg or sperm donor, to avoid high reproductive risk pregnancies.
• Anyone who wants to know if they are carrier of any condition included in the panel.
How is Genescreen® performed?
The DNA is first isolated from the peripheral blood and then amplified by PCR. Through a state-of-the-art technological process, named massively parallel sequencing (MPS), which uses Next Generation Sequencing (NGS) techniques with ILLUMINA sequencing instruments, 550 genes are completely sequenced at high read depth. The resulting genetic sequences are analysed via an advanced bioinformatics analysis, to assess the presence of potential mutations in the genes under investigation.
GeneScreen® test, unlike other carrier screening tests using targeted sequencing, performs full-exon sequencing of all the genes included on the panel, which allows a more comprehensive analysis of each gene and related diseases. Gene dosage analysis by Multiplex Ligation-dependent Probe Amplification (MLPA) of the SMN1 gene is performed for SMA carrier screening. Fluorescent PCR is used for Fragile-X carrier screen, to detect the (CGG)n repeat expansions in the promoter region of the FMR-1 gene.
Accuracy of the GeneScreen® test
Current DNA sequencing techniques are more than 99% accurate. While results of this testing are highly accurate, a negative result significantly reduces but does not eliminate the chance of being a carrier. The results of this testing, including the benefits and limitations, should be discussed with patients.
Sample type: Peripheral blood in EDTA
Time to result: 4 weeks
Click on the following link: GeneScreen® – Carrier screening test to download the complete list of investigated genes and diseases.