Comprehensive analysis of early pregnancy loss based on cytogenetic findings from a tertiary referral center

Background Pregnancy loss is one of the most common complications during pregnancy. Clinical consultation based on etiology analysis are critical for reducing anxiety and distress. This study aimed to perform a comprehensive analysis for products of conception (POC) in miscarriage based on genetic etiology and clinical information. Methods A retrospective study was conducted according to cytogenetic findings of 1252 POC from spontaneous pregnancy loss over 11 years. The frequencies and profiles of chromosomal abnormalities were discussed according to the classification of women with different maternal ages, previous miscarriage history, normal live birth history, and different modes of conception. Results A total of 667 (53.2%) chromosomal abnormalities were observed, including 592 (47.3%) cases of numerical abnormalities, 38 (3.0%) cases of structural abnormalities, and 37 (3.0%) cases of mosaic aberrations. In women above 40 years of age, the rates of chromosomal abnormalities and viable autosomal trisomy were significantly higher than those in women with ≤ 29, 30–34, and 35–39 years of age (p < 0.05). The frequency of abnormal karyotype in women with normal live birth history was 61.1%, significantly higher than 52.5% in women without normal live birth history (p < 0.05). There was no significant differences among women without, with 1–2, and ≥ 3 previous miscarriages regarding the rate of abnormal karyotype (p > 0.05); viable autosomal trisomy was less common in women with ≥ 3 previous miscarriages than women with < 3 miscarriages. The frequency of chromosomal abnormalities was 49.0% and 55.0% in women with assisted conception and natural conception (p > 0.05), respectively; monosomy X was more frequently detected in women with natural conception than assisted conception. Conclusion The frequencies and profiles of chromosomal abnormalities in early miscarriages are strongly associated with clinical information including maternal age, previous miscarriage, live birth history, and mode of conception. Cytogenetic analysis of POC should be recommended to women with a first miscarriage and women with normal live birth history.

Comprehensive analysis of early pregnancy loss based on cytogenetic findings from a tertiary referral center

Background Pregnancy loss is one of the most common complications during pregnancy. Clinical consultation and comprehensive understanding of the etiology are critical for reducing anxiety, distress, and depression. This study aimed to perform a comprehensive analysis for products of conception (POC) in miscarriage based on genetic etiology and clinical information. Methods Retrospective observation was performed on cytogenetic findings of 1252 POC form spontaneous pregnancy loss over an 11-year period. The frequencies and profiles of chromosomal abnormalities were discussed according to the classification of women with different maternal age, previous miscarriage history, normal live birth history, and different mode of conception. Results A total of 667 (53.2%) chromosomal abnormalities were observed, including 597 (47.7%) cases of numerical abnormalities, 33 (2.6%) cases of unbalanced structural abnormalities, 32 (2.6%) cases of mosaicism, and 5 (0.4%) cases of balanced rearrangement. In group of women above 40 years of age, the detection rates of chromosomal abnormalities and viable autosomal trisomy were significantly higher than those in groups of ≤ 29, 30 ~ 34, 35 ~ 39 years of age (p < 0.05). The detection rate of abnormal karyotype in women with normal live birth history was 61.1%, significantly higher than 52.5% in women without normal live birth history (p < 0.05). There was no significant difference among women without, with 1–2, and ≥ 3 previous miscarriages in the rate of abnormal karyotype (p > 0.05), and viable autosomal trisomy was less common in women with ≥ 3 previous miscarriages. The frequency of chromosomal abnormalities was 49.0% and 41.0% in women with assisted conception and natural conception (p > 0.05), respectively, and monosomy X was more frequently detected in women with natural conception. Conclusion The frequencies and profiles of chromosomal abnormalities in early miscarriages are strongly associated with clinical information including the maternal age, previous miscarriage, live birth history, and mode of conception. Even in women with a first miscarriage, or with a history of normal live births, chromosomal analysis of POC should be recommended for etiological assessment.

Chromosomal Aneuploidy Associated With Clinical Characteristics of Pregnancy Loss

ObjectiveEmbryonic aneuploidy is found in about half of sporadic pregnancy losses and the associations between the chromosomal aneuploidy and clinical characteristics of pregnancy loss remain unclear. The aims of this study were to evaluate the associations between chromosomal aneuploidy of products of conception (POC) and clinical features of pregnancy loss.MethodsWe conducted a retrospective cohort study including 1,102 women experienced singleton pregnancy loss and underwent chromosomal microarray analysis (CMA) detection of POC in our hospital. The results of molecular karyotypes and clinical features including maternal age, history of pregnancy loss, gestational age, vaginal bleeding and ultrasonographic findings were extracted from the medical records. χ2 test was used to compare categorical data between groups.Results631 (57.26%) POC specimens were detected to be chromosomal aneuploidy. Aneuploid rates were significantly higher in women &gt;35 years (P &lt; 0.001) and pregnancy loss &lt;11 gestational weeks (P = 0.044), but the rates of sex chromosome abnormalities and triploid were significantly higher in women ≤35 years (P &lt; 0.001, P = 0.002) and the rates of viable autosomal trisomy and sex chromosome abnormalities were significantly high in those women with pregnancy loss ≥11 weeks (P &lt; 0.001, P &lt; 0.001). Aneuploid rate was overall similar between the sporadic and the recurrent pregnancy loss (RPL) (P = 0.404), but the rate of sex chromosome abnormalities was higher in women with sporadic pregnancy loss (P = 0.03). Aneuploid rates were higher in subjects with yolk sac or embryo than in those without (P &lt; 0.001 and P = 0.001).ConclusionAdvanced maternal age is mainly associated with autosomal trisomy, while sex chromosome abnormalities and triploid might be more likely to occur in younger women. Aneuploidy rates might be no association with previous pregnancy loss except for sex chromosome abnormalities. Pregnancy loss without yolk sac or embryo might be less related to embryonic aneuploidy, and other factors should be emphasized.

Mosaic Trisomy 5: Prenatal Genetic Diagnosis and Outcomes of a New Case

Chromosomal mosaicism is defined as the presence of two or more different cell lines in an organism that originate from the same embryo. Trisomy of chromosome 5 is one of the most severe forms of autosomal trisomy and only seven cases of mosaic trisomy 5 have been reported to date. Mosaicism at prenatal level constitutes a challenge in genetic counseling, particularly in the case of mosaic trisomy 5, due to its low incidence. We report the case of a girl with a prenatal diagnosis of mosaic trisomy 5. The pre- and postnatal genetic tests (noninvasive prenatal testing, array comparative genomic hybridization, karyotype in amniotic fluid cells, karyotype in peripheral blood, and uniparental disomy analysis) revealed the fetal chromosomal status and indicated etiology giving rise to the mosaicism, suggesting a prezygotic meiotic error corrected through late trisomic rescue in the zygote.

A very rare partial trisomy syndrome: De novo duplication of 16q12.1q23.3 in a Turkish girl with developmental delay and facial dysmorphic features

Trisomy 16 is the most common type of autosomal trisomy associated with spontaneous abortion and is incompatible with life. Upon examining previously reported cases of partial chromosome 16q duplication, it was noted that the majority of cases had complex chromosomal abnormalities due to parental balanced chromosomal translocation carriage. The clinical presentation of very rare pure partial trisomy 16q cases was associated with congenital anomalies, facial dysmorphic findings and intellectual disability. In this study, we evaluated the physical characteristics and genetic data of an 8-month-old girl with developmental delay and facial dysmorphic features. Dysmorphic features including prominent metopic suture, synophrys, asymmetric head shape, triangular and asymmetric face, telecanthus, epicanthal folds, down-slanting palpebral fissures, microphthalmia of the left eye, anteverted nares, smooth and tented philtrum, microretrognathia, low-set posteriorly rotated ears, auricular pits, high-arched palate, thin upper lip and hypotonia were recorded. Her karyotype was 46,XX,add(16)(q24). To identify the extension of the duplicated section, array comparative genomic hybridization (aCGH) analysis was performed, which showed a de novo 29.8 Mb duplication [arr[hgl9] 16q12.1q23.3(52459169-82285105) x 3], interpreted to be pathogenic. We present this case report to clarify the clinical findings of a rare chromosomal anomaly, discuss the genes that may be related to the phenotype and advance the literature in terms of knowledge regarding genotypephenotype correlation.

Analysis of the Origin of Double Mosaic Aneuploidy in Two Cases

We present 2 cases of double mosaic aneuploidy harboring 2 or more different aneuploid cell lines, but no line with a normal chromosome constitution. One of these cases presented mosaicism of sex chromosome aneuploid cell lines (47,XXX/45,X) along with another line containing an autosomal trisomy (47,XX,+8), while the other case showed mosaicism of 2 different autosomal trisomy cell lines (47,XY,+5 and 47,XY,+8). To elucidate the mechanisms underlying these mosaicisms, we conducted molecular cytogenetic analyses. Genotyping data from the SNP microarray indicated that 2 sequential meiotic or early postzygotic segregation errors likely had occurred followed by natural selection. These cases suggest that frequent segregation errors and selection events in the meiotic and early postzygotic stages lead to this condition.

Analysis of the genomic expression profile in trisomy 18: insight into possible genes involved in the associated phenotypes

Trisomy 18, sometimes called Edwards syndrome, occurs in about 1 in 6000 live births and causes multiple birth defects in affected infants. The extra copy of chromosome 18 causes the altered expression of many genes and leads to severe skeletal, cardiovascular and neurological systems malformations as well as other medical problems. Due to the low rate of survival and the massive genetic imbalance, little research has been aimed at understanding the molecular consequences of trisomy 18 or considering potential therapeutic approaches. Our research is the first study to characterize whole-genome expression in fibroblast cells obtained from two patients with trisomy 18 and two matched controls, with follow-up expression confirmation studies on six independent controls. We show a detailed analysis of the most highly dysregulated genes on chromosome 18 and those genome-wide. The identified effector genes and the dysregulated downstream pathways provide hints of possible genotype–phenotype relationships to some of the most common symptoms observed in trisomy 18. We also provide a possible explanation for the sex-specific differences in survival, a unique characteristic of trisomy 18. Our analysis of genome-wide expression data moves us closer to understanding the molecular consequences of the second most common human autosomal trisomy of infants who survive to term. These insights might also translate to the understanding of the etiology of associated birth defects and medical conditions among those with trisomy 18.

Single-cell transcriptomics reveals diverse and complex gene expression alterations in human trisomy 18

Trisomy 18, commonly known as Edward’s syndrome, is the second most common autosomal trisomy among live born neonates. Multiple tissues including cardiac, abdominal, and nervous systems are affected by an extra chromosome 18. To delineate the complexity of anomalies of trisomy 18, we analyzed amniotic fluid cells from two normal and three trisomy 18 samples using single-cell transcriptomics. We identified six cell groups, which function in major tissue development such as kidney, vasculature, and smooth muscle, and display significant alterations in gene expression detected by single-cell RNA-sequencing. Moreover, we demonstrated significant gene expression changes in previously proposed trisomy 18 critical regions, and identified three new regions such as 18p11.32, 18q11, 18q21.32, which are likely associated with trisomy 18 phenotypes. Our results indicate complexity of trisomy 18 at the gene expression level and reveal genetic reasoning of diverse phenotypes in trisomy 18 patients.

Comparative cytogenetic analysis of early reproductive losses depending of maternal age

Aim. Human reproduction characterized by a high incidence of aneuploidies. Approximately 99 % of conceptions with anomalies of karyotype terminate of pregnancy loss, mainly during the first 14 weeks of intrauterine development. The frequency and spectrum of karyotype anomalies in the chorionic villus of early reproductive losses were studied depending of maternal age. Methods. Banding cytogenetic and interphase mFISH with the centromeric probe panel for chromosomes 13, 14, 15, 16, 17, 18, 21, 22, X and Y were used. Results. The contribution of different karyotype abnormalities in the genesis of the early reproductive losses depends on the age of the woman, namely, with age significantly increases the proportion of aneuploidy due to autosomal trisomies and reduced contribution of polyploidy and gonosomal monosomy. The main autosomal trisomy in the material of lost pregnancies from women under the age of 35 is 16, 21 and 15, 22, 13 and 18 in order of decreasing frequency, and from older women 16, 15, 22, 21, 13 and 14. Conclusions. The structure and rate of karyotype anomalies in the material of lost pregnancies varies with maternal age. Keywords: early reproductive loss, maternal age, karyotype abnormalities.