Related Experiment Video
Updated: Jan 25, 2026

Author Spotlight: Non-Invasive High-Resolution Measurement of Chlorophyll Synthesis During De-Etiolation
Published on: January 12, 2024
Uncertainty of fetal fraction determination in Non-Invasive Prenatal Screening by highly polymorphic SNPs
Marian Grendár1, Dušan Loderer2, Zuzana Laučeková3
1Bioinformatics Unit, Biomedical Center Martin, Jessenius Faculty of Medicine, Comenius University in Bratislava, Malá Hora 4C, 036 01 Martin, Slovakia.
Abstract:
Fetal fraction and the chromosome representation are the two key quantities used in Non-Invasive Prenatal Screening (NIPS) to determine the aneuploidy status of a fetus. Several methods for fetal fraction determination have been proposed in the literature, including a class of the methods, denoted snpFF, based on high-coverage targeted sequencing of highly polymorphic Single Nucleotide Polymorphisms (SNPs). The variant of snpFF, investigated here, has similar properties as the other variants of snpFF. We point out that the variability of the individual informative SNPs-based estimates of fetal fraction increases with the increase of fetal fraction. At 4% fetal fraction the Inter-Quartile Range (IQR) of the individual estimates of fetal fraction is around 3% and it increases to 6% at 15% fetal fraction. snpFF cannot detect fetal fraction below 2.5% because the number of informative SNPs becomes too small, even zero.
Related Concept Videos
Single Nucleotide Polymorphisms-SNPs
The Uncertainty Principle
Uncertainty in Measurement: Reading Instruments
Comparing Copy Number Variations and SNPs
Copy number variations or CNVs are the structural variations that cover more than 1kb of DNA sequence. The single nucleotide polymorphism (SNP), on the other hand, is a single nucleotide change or a point mutation that is found in more than 1%...
Uncertainty: Overview
Uncertainty in Measurement: Accuracy and Precision

