A karyotype test is a type of genetic testing. It looks at the size, shape, and number of chromosomes in a sample of cells from your body. Chromosomes are found in the cell nucleus, which is like the command center of a cell. Chromosomes contain your genes. Genes carry information, called DNA, that controls what you look like and how your body works. You inherit your chromosomes from your parents. Normally, all your cells (except for egg and sperm cells) have a set of the same 46 chromosomes. The chromosomes are grouped into 23 pairs. Each pair has two chromosomes, one coming from each parent. You may develop certain genetic disorders if your cells:

• Are missing whole chromosomes or pieces of chromosomes
• Have extra chromosomes or extra pieces of chromosomes

Quantitative Fluorescence PCR (QF-PCR) is a molecular-based technique employed for prenatal and postnatal diagnosis of rapid aneuploidy detection(RAD) of chromosomes 13, 18, 21, X, and Y.A technique based on the amplification of chromosome-specific DNA sequences (STR, short tandem repeats) polymorphic in length, is used to determine the presence of different alleles. Employing fluorescent primers, the amplified segments can be visualized and quantified as peak areas on automated DNA scanners. QF-PCR is rapid, cost-effective, almost entirely automated, small sample size with high accuracy, and can detect most abnormalities diagnosed by conventional karyotyping. Maternal Cell Contamination (MCC)Presence of maternal cells or DNA in fetal sample/DNA is known as Maternal Cell Contamination (MCC). Highly polymorphic STR (short tandem repeat) loci are used to differentiate between fetal and maternal samples/DNA, identify extent of Maternal Cell Contamination if present and thus avoid erroneous reporting. At present, the test can confidently identify 10% Maternal Cell Contamination or greater.

Karyotyping

• Abnormal fetal ultrasound and presenceof soft markers like hypoplastic nasalbone, Increased NT, Echogenic bowel etc.
• Maternal serum screening positive forchromosome aneuploidies
• NIPT positive for chromosomeaneuploidies
• Parental chromosomal rearrangement ormosaicism
• Previous history of recurrent miscarriages
• Previous fetus/baby with chromosomal abnormality

QFPCR

• Abnormal fetal ultrasound and presenceof soft markers like hypoplastic nasalbone, Increased NT, Echogenic bowel etc.
• Maternal serum screening positive forchromosome aneuploidies
• NIPT positive for chromosomeaneuploidies
• Parental chromosomal rearrangement ormosaicism
• Previous history of recurrent miscarriages
• Previous fetus/baby with chromosomal abnormality

MCC

One of the risks associated with prenatal /fetal testing is maternal cell contamination (MCC), which occurs when fetal specimen is mixed with maternal blood or tissue. The risk of MCC is associated with any fetal sample such as chorionic villus, POCs, Cord Blood, Amniotic Fluid, etc. If MCC is present, the maternal DNA may interfere with the fetal genetic testing thereby resulting in inaccurate reporting and diagnosis. This test will enable us to identify if a specific fetal sample has MCC. In order to perform this test a maternal blood sample is required along with the fetal sample.

Karyoytyping

A karyotype test looks for unusual changes in chromosomes. It may be used to:

• Check an unborn baby for chromosome problems
• Check you and/or your family members for specific chromosome problems if you:
• Have a genetic disorder that runs in your family
• Have symptoms that may be from a genetic disorder
• Find out if abnormal chromosomes are causing problems having children, including:
• Male or female infertility
• Miscarriages, if you have lost two or more pregnancies before 20 weeks
• Stillbirth
• Help diagnose and/or make treatment decisions for certain types of cancer and blood disorders

QFPCR

• Screening result suggests aneuploidy
• Advanced maternal age
• One major or at least two minor fetal structural defects found on ultrasound
• Previous fetus or child with aneuploidy
• Parent of this pregnancy has a structural chromosome abnormality (e.g.,translocation, inversion) involving chromosome 21, 13, 18, X, or Y
• Parent of this pregnancy has an extra chromosome (e.g., Down syndrome, XXX syndrome, Klinefelter syndrome)

MCC

The presence of both maternal and nonmaternal alleles for each fetal marker indicates the fetal specimen is not contaminated. MCC is confirmed when both alleles in the fetus are maternal.

Karyotyping - Chromosomal Analysis / Light Microscopy

QF PCR analysis includes amplification, detection and analysis of chromosome-specific DNA sequences known as genetic markers or small tandem repeats (STRs).

MCC - Testing includes amplification of highly polymorphic short tandem repeat (STR) markers with fluorescently labelled primers; fragment sizing of the resulting PCR products using a genetic analyzer.