The Contribution of QF-PCR and Pathology Studies in the Diagnosis of Diandric Triploidy/Partial Mole

Objective: the aim of our study was to assess the contribution of quantitative fluorescent polymerase chain reaction (QF-PCR) and pathology studies in the diagnosis of diandric triploidies/partial hydatidiform moles. Methods: this study included all fet al triploidies diagnosed by QF-PCR in chorionic villi or amniotic fluid in the 2 centers of BCNatal in which a maternal saliva sample was used to establish its parental origin. Pathology studies were performed in products of conception and concordance between a partial hydatidiform mole diagnosis and the finding of a diandric triploidy was assessed. Results: among 46 fetal triploidies, found in 13 ongoing pregnancies and in 33 miscarriages, there were 26 (56%) diandric triploidies. Concordant molecular (diandric triploidy) and pathology results (partial mole) were achieved in 14 cases (54%), while in 6 cases (23%) pathology studies were normal, and in the remaining 6 cases (23%) pathology studies could not be performed because miscarriage was managed medically. Conclusions: diandric triploidy is associated with partial hydatidiform mole and its diagnosis is crucial to prevent the development of persistent trophoblastic disease. QF-PCR analysis in chorionic villi or amniotic fluid provides a more accurate diagnosis of the parental origin of triploidy than the classical pathology studies.

Prenatal diagnosis of de novo small supernumerary marker chromosome 4q (4q11-q12): A case report

Background: Small supernumerary marker chromosomes (sSMCs) are chromosomal fragments with abnormal structures found in patients with fertility problems and developmental delay. They may be detected in amniotic cell karyotypes. sSMCs are categorized as hereditary or de novo. Here, we describe a case of prenatal de novo 4q11q12 sSMC and its molecular cytogenetic features which had no apparent phenotypic abnormality. Case: The fetus of a 36-yr-old pregnant woman was detected positive for Down’s syndrome (trisomy 21) at the 16th wk of gestation. Quantitative fluorescent polymerase chain reaction technique was applied for the rapid detection of numerical aneuploidy of chromosomes X, Y, 13, 18, and 21 microsatellites. Array comparative genomic hybridization (array CGH) technique was also conducted following the karyotype analysis of amniotic cells. The karyotype analysis was also done for the parents. Quantitative fluorescent polymerase chain reaction result revealed a male fetus with a normal chromosomal pattern, while the amniocentesis karyotype analysis identified a male fetus with a marker chromosome (47, XY, +mar), and the sSMC were existing in 100% of amniocyte metaphase spreads. The parents’ normal karyotypes indicated that the sSMC was de novo. Array CGH analysis revealed a 6.48-Mb duplication at 4q11q12. Eventually, the parents decided to terminate the pregnancy by legal abortion. Conclusion: Our study highlights the importance of the application of array CGH in combination with karyotype analysis for rapid and precise prenatal diagnosis of partial aneuploidy region. Key words: Prenatal diagnosis, Array CGH, Chromosome 4, Chromosome markers.

Quantitative Fluorescent Polymerase Chain Reaction for Prenatal Diagnosis and Its Application in Vietnam: A Literature Review

Early identification of fetal abnormalities is a huge challenge for modern obstetrics. Quantitative fluorescent polymerase chain reaction (QF-PCR) has quickly become an effective means of chromosome anomaly detection due to its advantages in terms of timing, manpower and accuracy. The QF-PCR results also make a significant change in clinicians’ attitude to some extent, assisting them providing parents with professional and valuable advice on pregnancy management. In this review, the advantages and drawbacks of QF-PCR will be explored. By reviewing studies published in Vietnamese Medical Journals, we conclude QF-PCR can become a potential screening test in the field of prenatal diagnosis.

Distribution of diandric and digynic triploidy depending on gestational age

Purpose To establish the distribution of diandric and digynic triploidy depending on gestational age. Methods 107 triploid samples tested prospectively in a single genetic department during a four-year period were analyzed for parental origin of triploidy by Quantitative Fluorescent Polymerase Chain Reaction (QF-PCR) (n=95) with the use of matching parental samples or by MS-MLPA (n=12), when parental samples were unavailable. Tested pregnancies were divided into three subgroups with regard to the gestational age at spontaneous pregnancy loss: <11 gestational weeks, 11–14 gestational weeks, and >14 gestational weeks. Results Diandric triploidy constituted overall 44.9% (46.5% in samples miscarried <11 gestational weeks, 64.3% in samples miscarried between 11 and 14 gestational weeks, and 27.8% in pregnancies which survived >14 gestational weeks). Conclusions The distribution of diandric and digynic triploidy depends on gestational age. The majority of diandric triploid pregnancies is lost in the first trimester of pregnancy. In the second trimester, diandric cases are at least twice less frequent than digynic ones.

Triploidy in a Live-Born Extremely Low Birth Weight Twin: Clinical Aspects

Triploidy is a rare chromosomal aberration characterized by a karyotype with 69 chromosomes. Triploid fetuses usually are miscarried in early pregnancy. We present a case of a triploid twin and a genetically unaffected co-twin, conceived through in vitro fertilization. A discordant growth was registered at 20 weeks of gestation. Cesarean section was performed at 355/7 gestational week. The second twin was extremely growth restricted female (780 g) with oligohydramnios and severe respiratory distress, and died at 20 hours of age. The autopsy revealed unilobar left lung, bilobar right lung, and cysts of the terminal bronchioles. Quantitative fluorescent polymerase chain reaction detected triploidy compatible pattern. So, early intrauterine growth restriction may be a sign of triploidy, which must be proven by pre or postnatal genetic testing.

Analysis of Y Chromosome Microdeletion and Karyotype in 516 Patients With Azoospermia

Background: To investigate the correlation between Y chromosome microdeletion and cytogenetic analysis in patients with azoospermia.Methods: A total of 516 patients with azoospermia were enrolled from March 2015 to December 2019. Karyotype analysis(G-banding) was performed with peripheral blood.Y-chromosome azoospermia factor (AZF) were detected by quantitative fluorescent polymerase chain reaction (QF-PCR).Results: Chromosome abnormality was detected in 66 of the 516 azoospermia patients, with an abnormal rate of 12.8% In addition, 7.8% cases(40/516) presented with Y-chromosome AZF microdeletions, in which 27 cases patients with karyotype of 46,XY(67.5%,27/40) and 13 cases of chromosome abnormalities (32.5%,13/40).Conclusion: The incidence of Y chromosome microdeletion was higher in the patients with karyotype of 46,XY. Conventional cytogenetics cannot directly reflect the microdeletions of Y chromosome. Therefore, the combination of this two detection methods can help to clarify the genetic causes of patients with azoospermia and provide a theoretical basis for clinical assisted reproductive technology.

Comprehensive Assessment of Plasma-Derived circ_0004771 as a Potential Biomarker in Tracking the Progression of Gastric Cancer

Background: Due to the lack of specific and sensitive detection indicators, most patients with gastric cancer (GC) are already in the advanced stage at the time of diagnosis, resulting in a higher mortality. Therefore, it is urgent to search for effective diagnostic biomarkers with high specificity that can be applied in clinic. Methods: We screened out circ_0004771 through circRNA sequencing performed on three pairs of GC tissues and corresponding paracancerous tissues. Both exonuclease digestion assay, agarose gel electrophoresis (AGE) and sanger sequencing verified the potential of circ_0004771 being a biomarker. Additionally, we established quantitative real-time fluorescent Polymerase Chain Reaction (qRT-PCR) to detect the expression level of circ_0004771 and evaluated the methodology. What’s more, we collected plasma samples from GC patients, precancerous patients and gastritis patients, and we constructed the receiver operating characteristic curve (ROC) to appraise its diagnostic efficacy. Meanwhile, we collected the clinicopathological data of the patients to analyze the relationship between the expression level of circ_0004771 and the pathological parameters of the patients. Results: The expression level of circ_0004771 is up-regulated both in GC tissues and cells compared to normal controls. Circ_0004771 can be served as a promising biomarker because of its stable cyclic structure and longer half-life. The expression level of plasma circ_0004771 can distinguish between GC patients and precancerous patients, GC patients and gastritis patients. The diagnostic efficiency of circ_0004771 is higher than that of CEA and CA199. Higher diagnostic efficiency can be achieved in combination diagnosis. The expression level of plasma circ_0004771 in GC patients decreased after surgery, which can track the recovery condition of patients. Besides, the downstream regulatory forecast indicates that circ_0004771 may act as miRNA sponge to regulate the progression of GC.Conclusion: Plasma circ_0004771 can be served as a less invasive tumor biomarker with high diagnostic values.

Antenatal detection of chromosomal abnormalities combining QF-PCR and cytogenetic analysis

Aim: To compare the diagnostic values and limitations of quantitative fluorescent polymerase chain reaction (QF-PCR) and conventional cytogenetic analysis in prenatal diagnosis of chromosomal abnormalities. Methods: A prospective study included simultaneous QF-PCR and cytogenetic analysis of 133 prenatal samples routinely obtained by amniocentesis or chorionic villus sampling (CVS). Additionally, QF-PCR analysis was performed on 14 tissue samples collected after termination of pregnancy (TOP) for which karyotyping could not be performed due to culture failure. Results: Among 133 analyzed prenatal samples, chromosomal abnormalities were diagnosed in 12 cases (9%), including 10 cases of numerical chromosomal aberrations and two cases with unbalanced structural rearrangements. Nine out of 12 chromosomal abnormalities were also detected with QF-PCR. However, all cases of major aneuploidies were successfully disclosed with QF-PCR, resulting in 100% detection rate for chromosomes 21, 18, 13, X and Y. Using a set of markers specific for chromosomes 21, 18 and 13, QF-PCR analysis of tissues collected after TOP revealed chromosomopathy in 21.4% of cases (two cases of trisomy 18 and one triploidy). A comparison of STR markers confirmed monozygosity in two monochorionic/diamniotic twin pregnancies. Conclusion: QF-PCR has been shown as a rapid and reliable method for prenatal diagnosis of the most common chromosomal aneuploidies, and as an adequate alternative to conventional karyotyping in cases where cytogenetic analysis is not possible due to failure of culturing process. However, conventional cytogenetics still presents a gold standard for the detection of structural aberrations and rare aneuploidies.