[Prenatal diagnosis and genetic counseling in 19 cases with 22q11.2 microduplications].

OBJECTIVE: Patients with 22q11.2 microduplications have highly variable clinical phenotypes. The clinical manifestations and prognosis of 19 fetuses carrying 22q11.2 microduplications were analyzed. METHODS: The fetuses were analyzed by single nucleotide polymorphism array (SNP array), which was followed by parental validation. Pregnancy outcome and clinical features of the newborns were analyzed in order to delineate genotype-phenotype correlation. RESULTS: Two fetuses were identified by karyotyping analysis of amniotic fluid samples. SNP array revealed that all have carried a 468.8 kb~3.4 Mb duplication in 22q11.2 region. Two couples have refused parental verification. Seven cases were inherited from the mother, 6 were from the father, and 4 cases were de novo in origin. Three couples opted termination of the pregnancy. One fetus perished at birth. Five newborns showed delayed growth, the remaining 10 were normal. CONCLUSION: The prenatal phenotype of fetuses carrying 22q11.2 microduplications are nonspecific, and the phenotypes of survivors may become more diverse along with increased age. Professional evaluation and long-term follow-up should be recommended.

Retrospective analysis of 4761 cases who underwent amniocentesis in southeast China.

The aim of this study was to examine the clinical and cytogenetic results of 4761 amniocentesis (AS) cases retrospectively in our clinic in southeast China. The prenatal diagnosis indications, detected chromosomal anomalies and the detection rate of chromosomal abnormalities were studied in 4761 patients who underwent AS between June 2014 and July 2016 retrospectively. Chromosomal abnormality was detected in 137 (2.88%) of the 4761 samples (89.1% numerical, 10.9% structural). The most frequent numerical chromosomal abnormality was trisomy 21 (59.0%). Clinically insignificant polymorphisms were the most frequent structural changes (n = 284). In our study, the frequency and proportion of abnormal karyotypes varied substantially across different maternal AS indications. Impact statement What is already known on this subject: Several studies on amniocentesis indications and results have been reported from China and from other countries. It has been known that the most common indications were the increased risk at maternal serum screenings (MSS) and advanced maternal age (AMA). What the results of this study add: In our study we make a conclusion that the indications and results of AS cases from our centre indicated the significance of genetic screening. What the implications are of these findings for clinical practice and/or further research: Our data could offer informative data for proper prenatal genetic counselling of pregnant women and their partners in Wuxi, China.

Novel rapid molecular diagnosis of fetal chromosomal abnormalities associated with recurrent pregnancy loss.

INTRODUCTION: Labor-intensive karyotyping is used as the reference standard diagnostic test to identify copy number variants (CNVs) in the fetal genome after recurrent pregnancy loss. Our aim was to present and evaluate a novel molecular assay called CNVplex that could potentially be used as an alternative method to conventional karyotyping for diagnosing fetal chromosomal abnormalities associated with recurrent pregnancy loss. MATERIAL AND METHODS: Using karyotyping as the reference standard, CNVplex was performed to identify fetal chromosomal abnormalities in the chorionic villus samples from 76 women experiencing at least two pregnancy losses. Its diagnostic accuracy, sensitivity, and specificity were evaluated to detect aneuploidies associated with recurrent pregnancy loss. Turnaround time and costs of CNVplex were also measured. RESULTS: Diagnostic accuracy of CNVplex in aneuploidies that are associated with recurrent pregnancy loss was 1.0 (95% CI 0.94-1.0), sensitivity was 100% (95% CI 0.89-1.0), and specificity was 100% (95% CI 0.875-1.0). Diagnostic accuracy of CNVplex was similar to that of karyotyping. Both karyotyping and CNVplex assay detected 27 autosomal trisomies, three 45,X monosomies, and three polyploidies. CNVplex also detected additional novel structural abnormalities of the fetal genome. Compared with karyotyping, CNVplex significantly (p = 0.001) reduced the waiting time by 13.98 days (95% CI 13.88-14.08) and the cost by US $241 (95% CI 234.53-247.47). CONCLUSIONS: CNVplex is a novel effective assay for diagnosing fetal chromosomal abnormalities associated with recurrent pregnancy loss. In the routine clinical work-up of recurrent pregnancy loss, diagnostic accuracy of CNVplex is comparable to that of conventional karyotyping but it requires less waiting time and has lower cost.

Rapid prenatal aneuploidy detection of BACs-on-Beads assay in 4961 cases of amniotic fluid samples.

OBJECTIVE: To evaluate the diagnostic value of the BACs-on-Beads (BoBs) assay for the rapid diagnosis of common aneuploidies and microdeletions. METHODS: A total of 4961 pregnant women admitted to the Wuxi Maternity and Child Health Care Hospital Affiliated to Nanjing Medical University from January 2017 to March 2019 were enrolled. BoBs assay and conventional karyotyping were applied to detect amniotic fluid samples with various indications for prenatal diagnosis. Chromosomal microarray analysis (CMA) and maternal cell contamination (MCC) tests were used for further validation. RESULTS: The overall abnormality detection rates (BoBs associated with karyotyping) were 4.25% (211/4961). The prenatal diagnosis success rate of karyotyping was 99.4% (4933/4961), compared to 100% (4961/4961) using the BoBs assays. The BoBs assay was similar to karyotyping for the detection of trisomy 21 (1.01%, 50/4961), trisomy 18 (0.40%, 20/4961), trisomy 13 (0.04%, 2/4961), and sex chromosomal aneuploidies (0.15%, 12/4961). The BoBs assay also identified sex chromosomal microduplications/microdeletions (1.73%, 86/4961), 22q11.2 microdeletions/microduplications (0.1%, 5/4961), and Cri du Chat syndrome (0.02%, 1/4961) which were missed by karyotyping. The sensitivity for the detection of numerical chromosomal abnormalities of the BoBs assay and karyotyping analysis was 100% (95/95, 95% CI: 1.0-1.0) and 98.9% (94/95, 95% CI: 0.969-1.010), respectively. The sensitivity of detecting structural chromosomal abnormalities in the BoBs assay was significantly higher than those of karyotyping (79.3%, 92/116, 95% CI: 0.718-0.868) versus 21.6% (25/116, 95% CI: 0.140-0.291) (p < .01). CONCLUSIONS: The BoBs assay is a reliable and rapid test for the detection of common aneuploidies and nine microdeletion syndromes with high sensitivity and accuracy in prenatal diagnosis. The assay can compensate for the limitations of karyotyping analysis.

Association between fetal chromosomal abnormalities and the frequency of spontaneous abortions.

Fetal chromosomal abnormalities are a common cause of spontaneous abortion. The present study investigated the association between fetal chromosomal abnormalities and the frequency of spontaneous abortions to enable clinicians to provide more informed genetic counseling. A total of 182 patients with a history of spontaneous abortions were recruited from July 2015 to August 2017. G-banding cytogenetic analysis and novel high-throughput ligation-dependent probe amplification (HLPA) techniques were performed on conception in all 182 patients to detect chromosomal abnormalities. Low-coverage whole-genome sequencing (WGS) was performed in 74 patients to detect copy number variations (CNVs). There were no significant differences in the incidence of karyotype abnormalities between patients with sporadic miscarriages (48.0%; SM group) and patients suffering recurrent spontaneous abortions (44.8%; RSA group). The maternal age was markedly higher in patients with 3 miscarriages. WGS indicated that the incidence of pathogenic CNVs in the RSA group was higher than that in the SM group, but the difference was not significant. In conclusion, a high incidence of karyotype abnormalities and pathogenic CNVs was observed in patients with spontaneous abortion. However, no association between fetal chromosomal abnormalities and the number of spontaneous abortions was observed. HLPA assays may be used as an alternative method for fetal karyotype analysis and determination of CNVs in patients with SM and RSA.

Prenatal hypoxia affected endothelium-dependent vasodilation in mesenteric arteries of aged offspring via increased oxidative stress.

Prenatal hypoxia can affect vascular functions in young offspring. However, there is limited knowledge regarding whether and how prenatal hypoxia influences vascular functions in aged offspring. This study compared the effects of prenatal hypoxia on the mesenteric arteries (MA) between a young adult and aged offspring and investigated the underlying mechanisms. Pregnant rats were randomly divided into the control and prenatal hypoxia groups. The vascular functions and molecular levels were assessed in 5-month-old (5 M) or 20-month-old (20 M) offspring. Prenatal hypoxia decreased acetylcholine-mediated vascular relaxations in 20-M but not 5-M offspring. Sodium nitroprusside-mediated relaxation curves were not altered by prenatal hypoxia in 5- and 20-M offspring. Prenatal hypoxia enhanced the contractile responses caused by phenylephrine, phorbol 12,13-dibutyrate, and 5-hydroxytryptamine only in 5-M offspring. The endothelial NO synthase (eNOS) activities were decreased along with downregulated eNOS mRNA expression and phosphorylated eNOS/total eNOS protein expression in 20-M offspring with prenatal hypoxia. The NADPH oxidase (NOX) inhibitor apocynin and superoxide dismutase (SOD) mimetic tempol restored the acetylcholine-mediated weaker relaxations in 20-M offspring with prenatal hypoxia. Enzyme-linked immunosorbent and dihydroethidium assay showed that prenatal hypoxia enhanced oxidative stress in 20-M offspring. Transmission electron microscopy showed that prenatal hypoxia damaged mitochondrial structures in the MA endothelial cells of 20-M offspring. Increased NOX2 protein expression and decreased SOD3 expression were found in 20-M offspring. The results demonstrated that endothelial dysfunction induced by intrauterine hypoxia occurred with aging via enhanced oxidative stress and decreased nitric oxide activities in aged offspring.

[Serum marker screening during the second trimester for prenatal diagnosis and predicting pregnancy outcome].

OBJECTIVE: To explore the clinical value of screening the serum markers during the second trimester of pregnancy in preventing congenital birth defect and predicting the pregnancy outcome. METHODS: Between November, 2011 and October, 2013, a total of 25 520 pregnant women (15-20+6 gestational weeks) underwent a screening test of triple serum markers including free beta-human chorionic gonadotrophin (free ßhCG), alpha-fetoprotein (AFP), and unconjugated estriol (µE3) during the second semester of pregnancy. The women identified by the screening test as having high risks were referred to invasive prenatal diagnosis by amniocentesis, or to color Doppler ultrasound examination for suspected patent neural tube defect (NTD), and their pregnancy outcomes were followed up. RESULTS: High-risk pregnancies were identified by the screening test in 4.91% (1254/25520) of the total cohort. Of the 818 patients receiving invasive prenatal diagnosis, the abnormal rate was 5.75% (47/818). The high-risk pregnancies identified by the screening test was associated with a significantly higher rate of abnormal outcomes compared with the low-risk pregnancies (1.91% vs 0.1%, P<0.01). Of the 210 high-risk cases of NTD, a definite diagnosis was established in 34 cases. We also found that pregnancies at an advanced age (>35 years) was associated with increased risks for trisomy 21 compared with those at younger ages (15% vs 1.65%P<0.01). The detection rate of abnormal karyotypes in pregnancies with an abnormal MoM value of a single marker was 3.17% (6/189). CONCLUSION: Screening tests of serum markers during the second trimester of pregnancy can be helpful to identify fetal chromosomal and anatomical anomalies, predict unfavorable pregnancy outcomes, and prevent birth defects in pregnancies at an advanced age. The MoM value of a single marker in the second trimester can be indicative of potential chromosomal abnormalities.

Angiotensin II-mediated vascular changes in aged offspring rats exposed to perinatal nicotine.

This study determined the long-term influence of prenatal nicotine exposure (PN) on blood pressure and vascular functions in the aged offspring rats. PN did not affect body weight and plasma adrenocorticotropic hormone level; however, it significantly reduced plasma angiotensin I and angiotensin II in both sexes. Systolic pressure in the male aged PN offspring was significantly higher. Angiotensin II-increased mean arterial pressure was higher in the aged PN offspring than that in the control regardless of sex. AT1 receptor blocker losartan, not AT2 receptor antagonist PD123319, reduced blood pressure in the aged PN rats more than that in the control. In the aged PN offspring, angiotensin II-increased vessel contraction and intracellular calcium level were higher in small mesenteric arteries. Acetylcholine-mediated vascular relaxation was weaker, and nitric oxide-related endothelial functions were damaged in aortic rings of PN offspring. Thickness of the wall of mesenteric arteries was increased in the male aged PN offspring. Ratio of AT1/AT2 receptors was significantly increased in the vessel of the PN group regardless of sex. These data provide new information on the very long term influence of PN on vascular structures and functions in the aged offspring, demonstrate that the aged PN female rats were not free of vascular risks after menopause, and suggest that multiple pathways may be involved in the detrimental alterations of the cardiovascular system of the PN rats.