ABSTRACT
OBJECTIVE: Objective of our study was optimization of noninvasive fetal sex detection from maternal plasma in pregnant women. STUDY DESIGN: Molecular DNA quantitative analyses in gonosomal loci. SETTING: The study was performed at Department of Medical Genetics and Fetal Medicine, University Hospital Olomouc. METHODS: Together 475 DNA samples isolated from maternal plasma in different weeks of pregnancy ranging from 4th w.g. to 37th w.g. Y chromosomal sequences in AMELY and TSPY were tested by refined quantitative fluorescent PCR using capillary electrophoresis. RESULTS: The method is able to distinguish 1% of Y chromosomal sequences of artificial mixtures. Investigation and assessment in cell free fetal DNA samples achieved 4.05% of false positivity and 7.15% of false negativity in Y sequence detection. CONCLUSION: Established method allows detecting fetal sex with high sensitivity and specificity. The method is possible to use also for quantitative purposes.
Subject(s)
Chromosomes, Human, Y/genetics , Sequence Analysis, DNA , Sex Determination Analysis/methods , DNA/blood , Electrophoresis, Capillary , Female , Humans , Polymerase Chain Reaction , PregnancyABSTRACT
BACKGROUND: Problems of maternal and foetal genotype differentiation of maternal plasma in pregnant women are solved generally by real-time systems. In this case the specific probes are used to distinguish particular genotype. Mostly gonosomal sequences are utilised to recognise the male foetus. This work describes possibilities in free foetal DNA detection and quantification by STR. METHODS AND RESULTS: Artificial genotype mixtures ranging from 0,2 % to 100 % to simulate maternal and paternal genotypes and 27 DNA samples from pregnant women in different stage of pregnancy were used for DNA quantification and detection. Foetal genotype was confirmed by biological father genotyping. The detection was performed in STR from 21st chromosome Down syndrome (DS) responsible region by innovated (I) QF PCR which allows to reveal and quantify even very rare DNA mosaics. The STR quantification was assessed in artificial mixtures of genotypes and discriminability of particular genotypes was on the level of few percent. Foetal DNA was detected in 74 % of tested samples. CONCLUSIONS: The IQF PCR application in quantification and differentiation between maternal and foetal genotypes by STR loci could have importance in non-invasive prenatal diagnostics as another possible marker for DS risk assessment.
Subject(s)
DNA/blood , Fetus/metabolism , Prenatal Diagnosis , Tandem Repeat Sequences , Down Syndrome/diagnosis , Female , Genotype , Humans , Male , Polymerase Chain Reaction , PregnancyABSTRACT
Polycyclic aromatic hydrocarbons (PAHs) were analysed in mosses (Hypnum cupressiforme) and pine needles (Pinus sylvestris) collected in the Czech Republic between 1988-94 at a regional background site in Kosetice, south Bohemia (1988-94) and two industrial sources. One industrial site (sampled 1989-91) in middle Moravia, was near a factory producing PAHs, carbon black and phthalates, the other (sampled 1991-93) near a coal and gas fuel production plant in western Bohemia. Selected chlorinated pesticides and polychlorinated biphenyl congeners were also analysed in samples at the regional background site. This study clearly shows that vegetation sampling can be used to show spatial differences in the atmospheric burden of a range of persistent organic pollutants with differences in the mixtures of compounds reflecting differences in their regional or local use/atmospheric emission.
