Polyploidy in First and Second Trimester Pregnancies in Romania - a Retrospective Study

Approach and Management of Pregnancies with Risk Identified by Non-Invasive Prenatal Testing

This study represents our second investigation into NIPT, involving a more extensive patient cohort with a specific emphasis on the high-risk group. The high-risk group was subsequently divided into two further groups to compare confirmed cases versus unconfirmed via direct methods. The methodology encompassed the analysis of 1400 consecutive cases from a single genetic center in western Romania, where NIPT was used to assess the risk of specific fetal chromosomal abnormalities. All high-risk cases underwent validation through direct analysis of fetal cells obtained via invasive methods, including chorionic villus sampling and amniocentesis. The confirmation process utilized QF-PCR, karyotyping, and SNP-Array methods customized to each case. Results: A high risk of aneuploidy at NIPT was identified in 36 out of 1400 (2.57%) cases and confirmed in 28 cases. The study also detected an increased risk for copy number variations (CNVs) in 1% of cases, confirmed in two instances involving one large microdeletion and one large microduplication. Trisomy 21 was the exclusive anomaly where NIPT confirmed all cases with identified risk. High-risk NIPT results which were not validated by invasive methods, were classified as false positives; parents in these cases determined to continue the pregnancy. In conclusion, NIPT can serve as a screening method for all pregnancies; however, in high-risk cases, an invasive confirmation test is strongly recommended.

Prenatal detection and molecular cytogenetic characterization of Xp deletion and Xq duplication: a case report and literature review

BACKGROUND

Copy number variation (CNV) of X chromosome can lead to a variety of neonatal abnormalities, especially for male fetuses. In recent years, due to the high sensitivity and high specificity of NIPS, its application has gradually expanded from chromosome aneuploidy to CNV. Few prenatal cases involving the detection of Xq duplication and deletion by NIPS have been reported, but it is of great significance for genetic counseling.

CASE PRESENTATION

A 36-year-old woman was referred for prenatal diagnosis and genetic counseling at 17 weeks of gestation because of abnormal result of noninvasive prenatal screening (NIPS). Multiple congenital malformations, hydrocephalus, and enlarged gallbladder were observed by prenatal ultrasound. Amniocentesis revealed the karyotype of the fetus as 46, XN, add(X) (p22.2) and the result of chromosomal microarray analysis was arr[hg19] Xq27.1q28(138,506,454-154896094) × 2 and arr[hg19] Xp22.33p22.32(168,551-5,616,964) × 1. CNV-seq showed that the mother shares a 16.42 Mb duplication in the Xq27.1-q28 region and a 2.97 Mb deletion in the Xp22.33-p22.32 region. After genetic counseling, the couple chose to terminate the pregnancy.

CONCLUSION

The combination of NIPS and CMA would be of values in detection of subchromosomal duplications and/or deletions at fetal stage. The detection of X chromosome aberration in a male fetus should give suspicion of the possibility of maternal inheritance.

Polyploidy Phenomenon as a Cause of Early Miscarriages in Abortion Materials

Objectives

Chromosomal abnormalities are an important cause of especially early miscarriages. The aim of this study was to analyze the chromosomal aberrations and determine the frequencies of numerical and structural chromosome abnormalities in spontaneous abortion materials.

Methods

This was a prospective research and ninety two abortion samples obtained from women who had one or more miscarriages were included in the study. Conventional karyotype analysis was performed on each sample to identify possible chromosomal abnormalities.

Results

By karyotype analysis, 11 polyploidy cases, (9 triploids and 2 tetraploids), 8 trisomies (one of which was mosaic), 2 monosomies (monosomy X), 1 isochromosome, 1 Xq deletion, and 4 translocations were detected in abortion materials. Isochromosome and Xq deletion cases were also mosaic. In addition, five polymorphic variants were revealed. We found higher paternal age in polyploidy cases.

Conclusion

The most common anomaly we found in abortion materials was polyploidy. This was followed by aneuploidy (trisomy and monosomy). Polyploidy (triploidy or tetraploidy) emerged as an important cause in cases of spontaneous abortion. Paternal age may be associated with polyploidy especially triploidy.

A chromosomal microarray analysis-based laboratory algorithm for the detection of genetic etiology of early pregnancy loss

Background: Chromosomal abnormalities are a major cause of early pregnancy loss. However, models synthesizing existing genetic technologies to improve pregnancy outcomes are lacking. We aim to provide an integrated laboratory algorithm for the genetic etiology of couples who experienced pregnancy loss. Methods: Over a 6-year period, 3,634 products of conception (POCs) following early pregnancy loss were collected. The clinical outcomes from a laboratory algorithm based on single nucleotide polymorphism (SNP) array, fluorescence in situ hybridization (FISH), and parental chromosomal karyotyping assays were comprehensively evaluated. Results: In total, 3,445 of 3,634 (94.8%) POCs had no maternal-cell contamination. Of those POCs, the detection rate of abnormal results was 65.2% (2,247/3,445), of which 91.2% (2,050/2,247) had numerical chromosomal abnormalities, 2.7% (60/2,247) had copy-number variations (CNVs) ≥10 Mb, 2.7% (61/2,247) had CNVs of terminal deletion and duplication, 2.8% (62/2,247) had CNVs <10 Mb, and 0.6% (14/2,247) had uniparental disomy. Furthermore, FISH confirmed 7 of the 60 POCs with mosaic aneuploids below 30% based on the SNP array results as tetraploid. Of the 52 POCs with CNVs of terminal deletion and duplication, 29 couples had balanced rearrangements based on chromosomal karyotyping. Conclusion: The integrated SNP array-based algorithm combined with optional FISH and parental chromosomal karyotyping is an effective laboratory testing strategy, providing a comprehensive and reliable genetic investigation for the etiology of miscarriage, regardless of the number of miscarriages and the method of conception.

Genetic Counseling and Management: The First Study to Report NIPT Findings in a Romanian Population

Background and Objectives: Non-invasive prenatal testing (NIPT) has been confirmed as the most accurate screening test for trisomies 21, 18, 13, sex chromosomes aneuploidies and several microdeletions. This study aimed to assess the accuracy of cell free DNA testing based on low-level whole-genome sequencing to screen for these chromosomal abnormalities and to evaluate the clinical performance of NIPT. Materials and Methods: 380 consecutive cases from a single genetic center, from Western Romania were included in this retrospective study. Cell-free nucleic acid extraction from maternal blood, DNA sequencing and analysis of sequenced regions were performed by BGI Hong Kong and Invitae USA to determine the risk of specific fetal chromosomal abnormalities. In high-risk cases the results were checked by direct analysis of fetal cells obtained by invasive methods: 6 chorionic villus sampling and 10 amniocenteses followed by combinations of QF-PCR, karyotyping and aCGH. Results: NIPT results indicated low risk in 95.76% of cases and high risk in 4.23%. Seven aneuploidies and one microdeletion were confirmed, the other results were found to be a false-positive. A gestational age of up to 22 weeks had no influence on fetal fraction. There were no significant differences in fetal fraction across the high and low risk groups. Conclusions: This is the first study in Romania to report the NIPT results. The confirmation rate was higher for autosomal aneuploidies compared to sex chromosome aneuploidies and microdeletions. All cases at risk for trisomy 21 were confirmed. Only one large fetal microdeletion detected by NIPT has been confirmed. False positive NIPT results, not confirmed by invasive methods, led to the decision to continue the pregnancy. The main limitation of the study is the small number of patients included. NIPT can be used as a screening method for all pregnancies, but in high-risk cases, an invasive confirmation test was performed.

Differentially expressed circulating microRNAs associated with idiopathic recurrent pregnancy loss

Recurrent pregnancy loss (RPL) is a major pregnancy complication which reportedly affects 2-3% of all pregnancies. Currently, RPL lacks an effective therapy and a reliable diagnostic and prognostic biomarker. Circulating microRNAs were recently described as potential biomarkers of pregnancy-associated complications. The aim of this study was to determine microRNA expression patterns in the plasma of RPL patients as potential early biomarker of RPL. Study subjects comprised 20 women with early RPL (miscarriage at 8-12 weeks of gestation), and 20 age- and gestation-matched multiparous control women. Circulating microRNAs were extracted from maternal plasma, and the differential microRNA expression were determined using customized pathway-focused miRNA profiler kit. Of the 10 differentially-expressed microRNAs identified, Hsa-let-7e, Hsa-miR-221-3p, Hsa-miR-16, Hsa-miR-519d, Hsa-miR-184, Hsa-miR-410 were upregulated, while Hsa-miR-21, Hsa-miR-125, Hsa-let-7a, Hsa-let-7d were downregulated in RPL cases as compared to control women. Of these, 5 novel microRNAs were reported for the first time to be associated with RPL. These comprised Hsa-let-7e, Hsa-miR-519d, Hsa-miR-410 which were upregulated, and Hsa-let-7a, Hsa-let-7d which were downregulated in RPL. While its association with RPL was reported earlier, this study is also the first to report on the upregulation of Hsa-miR-184 in circulating fluids in association with RPL. The study provides for understanding circulating microRNAs expression pattern in RPL which may be involved in its pathogenesis and demonstrates their potential role as noninvasive diagnostic and prognostic biomarkers for RPL.

De novo 8p21.3→ p23.3 Duplication With t(4;8)(q35;p21.3) Translocation Associated With Mental Retardation, Autism Spectrum Disorder, and Congenital Heart Defects: Case Report With Literature Review

Duplications of chromosome 8p lead to rare genetic conditions characterized by variable phenotypes. 8p21 and 8p23 duplications were associated with mental retardation but only 8p23 duplication was associated with heart defects. 8p22→ p21.3 duplications were associated with an autism spectrum disorder in several cases. We present a rare case with a de novo duplication of the entire 8p21.3→ p23.3 region, documented by karyotype, FISH, and array CGH, with t(4;8)(q35;p21.3) translocation in a 7 years-old girl. She was referred for genetic counseling at the age of 20 months due to mild dysmorphic facial features, psychomotor retardation, and a noncyanotic heart defect. Another examination carried out at the age of 5 years, enabled the diagnosis of autism spectrum disorder and attention deficit hyperactivity disorder. Upon re-examination after two years she was diagnosed with autism spectrum disorder, attention deficit hyperactivity disorder, liminal intellect with cognitive disharmony, delay in psychomotor acquisitions, developmental language delay, an instrumental disorder, and motor coordination disorder. Cytogenetic analysis using GTG technique revealed the following karyotype: 46,XX,der(4),t(4;8)(q35;p21.3). The translocation of the duplicated 8pter region to the telomeric region 4q was confirmed by FISH analysis (DJ580L5 probe). Array CGH showed: arr[GRCh37]8p23.3p21.3(125733_22400607) × 3. It identified a terminal duplication, a 22.3 Mb copy number gain of chromosome 8p23.3-p21.3, between 125,733 and 22,400,607. In this case, there is a de novo duplication of a large chromosomal segment, which was translocated to chromosome 4q. Our report provides additional data regarding neuropsychiatric features in chromosome 8p duplication. The phenotypic consequences in our patient allow clinical-cytogenetic correlations and may also reveal candidate genes for the phenotypic features.

CHARGE syndrome associated with (I1460Rfs*15) frameshift mutation of CHD7 gene in a patient with arteria lusoria and horseshoe kidney

CHARGE syndrome is an autosomal dominant condition caused by mutations in the chromodomain helicase DNA binding protein 7 (CHD7) gene. The present study reported on the case of a 16-month-old female with plurimalformative syndrome, whose etiology was identified by clinical whole-exome sequencing (WES) analysis. Clinical and follow-up assessments identified multiple craniofacial dysmorphisms, congenital defects and functional symptoms, including dysphagia and Marcus Gunn jaw winking synkinesis. Trio-WES analysis was performed for the patient and their parents and the presence of CHARGE syndrome was further indicated using single-molecule real-time sequencing. A de novo pathogenic variant, c.4379_4380del (p.Ile1460Argfs^*15), was identified in exon 19 of the CHD7 gene, which resulted in a premature translational stop signal. Trio-WES analysis was used for further investigation, indicating that neither of the patient's parents had the mutation and confirming its de novo nature. To the best of our knowledge, the case of the present study was the first reported case of CHARGE syndrome in Romania with congenital defects including an aberrant right subclavian artery and a horseshoe kidney. CHARGE syndrome was diagnosed in the patient based on the pathogenic mutation in the CHD7 gene. To the best of our knowledge, the present case report is the first to suggest that the CHD7 gene variant is associated with CHARGE syndrome.