胎儿DNA浓度分数(Fetal fraction,简称FF),是指胎儿胎盘来源的cfDNA占母体血浆cfDNA总量的百分比,计算公式:FF=胎儿cfDNA/(胎儿cfDNA+母体cfDNA)。在孕10-20周,FF平均值在10%-15%之间。 FF为什么对NIPT检测效能很重要? FF是影响NIPT检测性能的重要参数...
To compare available analysis methods for determining fetal fraction on single read next generation sequencing data. This is important as the performance of non-invasive prenatal testing (NIPT) procedures depends on the fraction of fetal DNA.We tested six different methods for the detection of fetal...
The fetal fraction, or percentage of total cell-free DNA (cfDNA) in a sample derived from the fetus, can impact NIPT results and profitability.
This is important as the performance of non-invasive prenatal testing (NIPT) procedures depends on the fraction of fetal DNA.We tested six different methods for the detection of fetal fraction in NIPT samples. The same clinically obtained data were used for all methods, allowing us to assess ...
Yourgene Health plc, a leading international molecular diagnostics group, presented data demonstrating that prolonged storage of blood in EDTA tubes is compatible with non-invasive prenatal testing when using size selection to enrich the feta...
The use of low molecular weight heparin reduced the fetal fraction and rendered the cell-free DNA testing for trisomy 21 false negative. Ultrasound Obstet Gynecol; e-pub ahead of print 24 March 2017. 25. Taylor-Phillips S, Freeman K, Geppert J, et al. Accuracy of non-invasive prenatal ...
In one of the presentations, the presenter explained how a patient had received a positive NIPT result that ultimately was found to derive from what’s called “placental mosaicism.”“Mosaicism” occurs in the case of triploidy where there is a triplicate of a chromosome in some, but not all...
van Beek DM, Straver R, Weiss MM, et al. Comparing methods for fetal fraction determination and quality control of NIPT samples. Prenat Diagn. 2017;37:1‐5.van Beek DM, Straver R, Weiss MM, Boon EMJ, Huijsdens-van Amsterdam K, Oudejans CBM, et al. Comparing methods for fetal ...
Over those regions, there are more possible combinations alleles at a given SNP, meaning more bands. In this example, the fetal fraction for fetus 1 is less than that for fetus 2. (c) When trisomy is present in a monozygotic twin pregnancy, the number of bands change, with the number ...