Screening for Down's syndrome, Edwards' syndrome and Patau's syndrome is offered routinely to thousands of women each year as part of standard antenatal care. For those women identified as being at high risk of carrying a fetus with one of these conditions, chorionic villus sampling (10-12 weeks) or amniocentesis (14-18 weeks) is offered. Invasive testing may also be offered in pregnancies where a sex chromosome complement disorder is suspected.
Rapid Prenatal Aneuploidy Analysis
Testing of this invasive sample to give a diagnostic result was traditionally undertaken using standard cytogenetic techniques. These techniques, involving tissue culture and microscopic analysis, can take up to 14 days to provide a diagnosis. In particular, fluorescent in situ Hybridisation (FISH) using interphase cells is expensive, time consuming and unsuitable for high throughput use.
Yourgene’s range of QST*R kits take advantage of the QF-PCR (Quantitative Fluorescence-Polymerase Chain Reaction) technique. Using PCR amplification, fluorescent dye labelled primers target highly polymorphic regions of DNA sequence, short tandem repeats (STRs), located on the chromosomes of interest.
Each targeted STR marker is specific to the chromosome on which it is located, thus the copy number of the STR marker can be diagnostic of the copy number of the chromosome. In an individual unaffected by a trisomy, two alleles of a chromosome specific STR are determined by the QF-PCR technique as two peaks in a 1:1 ratio. The observation of an extra STR allele as either a three peak pattern in a 1:1:1 ratio or two peak pattern in a 2:1 or 1:2 peak ratio is diagnostic of the presence of an additional sequence, which in turn may represent an additional chromosome as in the case of a trisomy.
Yourgene® QST*R Base is a highly multiplexed, single tube assay containing a total of 22 markers. Autosomal markers are used to detect the three most common viable autosomal trisomies: trisomy 21 (Down's syndrome), trisomy 18 (Edwards’ syndrome) and trisomy 13 (Patau's syndrome). Additional markers on the sex chromosomes X and Y, including a specific marker for the quantification of the number of X chromosomes, are useful in the diagnosis of sex chromosome aneuploidies. The chosen markers are highly informative with results obtained in >99% of samples. Reflex kits containing additional markers are available for follow up analysis in the rare case of an uninformative result.
Yourgene® QST*R Base
A total of 22 markers for chromosomes 13,18, 21, X and Y and will detect the most common viable autosomal trisomies and sex chromosome aneuploidies
Yourgene® QST*R Base Lite
A total of 16 markers for the detection of the 3 most common viable autosomal trisomies (13, 18 and 21)
Yourgene® QST*R Plus Trisomy 13
Detects additional chromosome 13 specific markers to supplement QST*R and QST*Rplusv2 if required
Yourgene® QST*R Plus Trisomy 18
Detects additional chromosome 18 specific markers to supplement QST*R and QST*Rplusv2 if required
Yourgene® QST*R Plus XY
Detects a total of 12 markers for both the X and Y chromosomes. It can be used to detect sex chromosome aneuploidies
Yourgene® QST*R Plus Trisomy 21 Zeta
Reflex testing for chromosome 21 – 7 STR markers in total
Yourgene® QST*R range previously known as Elucigene® QST*R range.
Yourgene® QST*R Plus Trisomy 21
Detects additional chromosome 21 specific markers to supplement QST*R and QST*Rplusv2 if required
The Yourgene® QST*R range of products is available as CE-marked in vitro diagnostic products (IVD) or Research Use Only (RUO) products. See our Product Menu for further information.
Rapid Prenatal Aneuploidy Analysis
Individual results can be obtained within a few hours of receipt of samples. In routine use, turnaround reporting times of less than 24 hours from sample receipt are easily achievable. QF-PCR does not require cell culture, resulting in reduced failure rates and cost savings.
Flexibility and simplicity from sample to report
The Yourgene® QST*R range is compatible with most commonly employed DNA extraction protocols, thermal cyclers and capillary electrophoresis instruments. This flexibility in approach is complemented by simple and easy to use analysis software for reporting.
Results can be analysed through either Life Technologies GeneMapper™ or SoftGenetics GeneMarker® software. GeneMarker’s® operation now includes a customised Trisomy Analysis function.
By selecting BPG (Best Practice Guidelines) settings within the Trisomy Analysis function users can quickly and accurately measure allele ratios to obtain a full patient sample report within minutes.
- Simple set up – one tube per sample
- Rapid – minimum hands on time, just add DNA
- One step protocol – DNA extraction to PCR
- Reduced risk of sample mix-up
- Efficient – fewer consumables, reduced cost
- Validated for use on the ABI3500 and SeqStudio Genetic Analyzers
- Highly informative – multiplexed 5 dye chemistry
- No post-PCR manipulation
- One capillary per sample
- Cost effective – less instrument consumables
- GeneMarker™ and GeneMapper® software applications
- Simple data review and analysis
- Easy to use intuitive software
- Informative single page report
- No data transfer required
Performance you can rely on
100% Accuracy, Repeatability & Reproducibility
Was determined to be 100% positive percent agreement (PPA), 100% negative percent agreement (NPA), and 100% overall agreement (OA) compared to karyotyping (the ‘Gold Standard’). Accuracy of the QST*R range of products was assessed by evaluating over 300 samples.
Results showed 100% PPA, 100% NPA, and 100% OA. This data provides evidence that the QST*R range of products produce consistently repeatable results.
Results showed 100% PPA, 100% NPA, and 100% OA. This data provides evidence that the QST*R range of products produce consistently reproducible results
Yourgene ® QST*R Base reduces turnaround times and saves money compared to competitor product
Quantitative fluorescent–polymerase chain reaction (QF-PCR) has been shown to be a reliable and efficient methodology for the rapid diagnosis of the common autosomal and sex chromosome aneuploidies during pregnancy. Using this approach, chromosomes are ‘counted’ by way of assessment of height ratios or peak area for informative short tandem repeat (STR) markers.
Yourgene® QST*R Base, previously known as Elucigene® QST*RplusV2
Inkster A, Thomas M. A, Gamache N. S, Chan M, Stenroos P, Chernos J. E, & Argiropoulos B. A Challenging Prenatal QF-PCR Rapid Aneuploidy Test Result Caused by a Maternally Inherited Triplication within Chromosome Xq26. Cytogenetic and genome research, 156(1), 5-8. 2018 December.
Genetic analysis of STR markers on chromosome 21 in a Han population from southeast China. Zhu, Y N, Lu S M, Wang M, Shen F X, Chen Y, & Hu J J. Genetics and Molecular Research. 2015 March 6.
Scott P, Podemski L, Baptista Wyatt K, Walker C, Haase S M, Elyas B G, ... & Hume S L. Toward Optimal Detection of the Common Prenatal Aneuploidies by Quantitative Fluorescent–Polymerase Chain Reaction: Comparison of Two Commercial Assays. Genetic testing and molecular biomarkers. 2012 August 16.
Cho E H, Park B Y N, Kang Y S, & Lee E H. Validation of QF–PCR in a Korean population. Prenatal diagnosis. 2009 March 24.
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