NIFT Plus by GenePlanet is an advanced non-invasive prenatal test (NIPT) designed to detect a wide range of fetal chromosomal abnormalities, including common aneuploidies and clinically significant microdeletion syndromes. This test expands beyond standard NIPT by incorporating the detection of subchromosomal deletions, which are often undetectable through conventional screening methods. Utilizing next-generation sequencing (NGS) and sophisticated bioinformatics, NIFT Plus provides an early and accurate genetic analysis using only a maternal blood sample, avoiding the risks associated with invasive diagnostic procedures such as amniocentesis or chorionic villus sampling (CVS).
The test is available from the 10th week of pregnancy when sufficient fetal DNA is present in maternal circulation for analysis. Cell-free fetal DNA (cffDNA), originating from the placenta, is isolated from maternal blood and analyzed through massively parallel sequencing (MPS). This technique sequences millions of DNA fragments simultaneously, allowing precise quantification of chromosomal content and subchromosomal deletions. Bioinformatics algorithms differentiate between maternal and fetal DNA, ensuring accurate detection even in cases where the fetal fraction is low.
Comprehensive Screening for Chromosomal Aneuploidies
NIFT Plus screens for the most common trisomies, which result from an extra copy of a chromosome:
- Trisomy 21 (Down Syndrome): Characterized by intellectual disability, distinct facial features, and an increased risk of congenital heart defects. Occurs in 1 in 700 live births.
- Trisomy 18 (Edwards Syndrome): A severe disorder associated with profound developmental delays, congenital heart defects, and a high neonatal mortality rate. Occurs in 1 in 5.000 pregnancies.
- Trisomy 13 (Patau Syndrome): A rare condition causing severe neurological and developmental impairments, including brain malformations, cleft lip and palate, and congenital heart defects. Affects 1 in 10.000 live births.
In addition to trisomies, the test detects sex chromosome aneuploidies, which involve abnormalities in the number of X and Y chromosomes:
- Turner Syndrome (45, X): Affects females and results in short stature, ovarian dysfunction, and cardiovascular abnormalities.
- Klinefelter Syndrome (47, XXY): Affects males, leading to tall stature, delayed speech development, and infertility.
- Triple X Syndrome (47, XXX): Affects females, associated with mild learning difficulties and delayed speech and language development.
- Jacob’s Syndrome (47, XYY): Affects males, often leading to tall stature and increased risk of learning and behavioral challenges.
Microdeletion Syndrome Detection: Expanding the Scope of Prenatal Screening
Unlike standard NIPT, NIFT Plus detects clinically significant microdeletion syndromes caused by the loss of small DNA segments on specific chromosomes. These deletions can lead to severe congenital disorders that impact intellectual, developmental, and physical health. The test identifies:
- 22q11.2 Deletion Syndrome (DiGeorge Syndrome): Affects the heart, immune system, and brain development, leading to congenital heart defects, cleft palate, immune deficiencies, and learning disabilities. It is one of the most common microdeletion syndromes, occurring in 1 in 4,000 live births.
- Prader-Willi Syndrome (15q11-q13 deletion): This leads to intellectual disabilities, compulsive eating behaviors, low muscle tone, and hormone imbalances.
- Angelman Syndrome (15q11-q13 deletion): Causes severe developmental delays, epilepsy, and issues with speech and movement coordination.
- Cri-du-chat Syndrome (5p deletion): Characterized by a high-pitched, cat-like cry in newborns, intellectual disabilities, and distinct facial features.
- 1p36 Deletion Syndrome: This leads to developmental delays, intellectual disability, seizures, and congenital heart defects.
High-depth sequencing and advanced computational models can detect subchromosomal deletions. These models recognize slight genetic imbalances that traditional karyotyping and fluorescence in situ hybridization (FISH) tests often fail to detect.
Scientific Methodology: High-Precision Genomic Analysis
The accuracy of NIFT Plus is ensured through whole-genome sequencing and bioinformatics techniques, allowing for comprehensive chromosomal analysis. The testing process involves:
- Cell-Free DNA Extraction: Fetal DNA fragments are isolated from maternal blood and prepared for sequencing.
- Massively Parallel Sequencing (MPS) involves simultaneously sequencing millions of DNA fragments to detect aneuploidies and deletions.
- Fetal Fraction Analysis: The percentage of fetal DNA in maternal blood is measured to ensure test accuracy.
- Computational Variant Calling: Statistical models compare observed DNA fragment distributions against a reference genome, allowing identification of chromosomal abnormalities.
Clinical Significance and Applications
NIFT Plus is particularly valuable in pregnancies where:
- Ultrasound abnormalities suggest a possible genetic disorder.
- Advanced maternal age increases the risk of chromosomal abnormalities.
- A history of genetic conditions in previous pregnancies raises concerns.
- A need for broader chromosomal analysis exists beyond standard aneuploidy screening.
By providing comprehensive chromosomal screening, NIFT Plus enhances early genetic risk assessment and allows for better-informed decisions regarding pregnancy management. The integration of microdeletion detection makes it a powerful tool in modern non-invasive prenatal testing, offering a detailed, high-precision analysis of fetal chromosomal health with unmatched accuracy and safety.
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