Genetic testing for fetal loss of heterozygosity using single nucleotide polymorphism array and whole-exome sequencing.

The study explored the clinical significance of fetal loss of heterozygosity (LOH) identified by single-nucleotide polymorphism array (SNP array). We retrospectively reviewed data from pregnant women who underwent invasive diagnostic procedures at prenatal diagnosis centers in southeastern China from December 2016 to December 2021. SNP array was performed by the Affymetrix CytoScan 750 K array platform. Fetuses with LOH were further identified by parental verification, MS-MLPA, and/or trio whole-exome sequencing (trio-WES). The genetic results, fetal clinical manifestations, and perinatal outcome were analyzed. Of 11,062 fetuses, 106 (0.96%) had LOH exhibiting a neutral copy number, 88 (83.0%) had LOH in a single chromosome, whereas 18 (17.0%) had multiple LOHs on different chromosomes. Sixty-six fetuses had ultrasound anomalies (UAs), most frequently fetal growth restriction (18/66 (27.3%)). Parental SNP array verification was performed in 21 cases and trio-WES in 21 cases. Twelve cases had clinically relevant uniparental disomy, five had pathogenic variants, four had likely pathogenic variants, six had variants of unknown significance, and eight had identity by descent. The rate of adverse pregnancy outcomes in fetuses with LOH and UAs (24/66 (36.4%)) was higher than in those without UAs (6/40 (15.0%)) (p < 0.05). LOH is not uncommon. Molecular genetic testing techniques, including parental SNP array verification, trio-WES, methylation-specific multiplex ligation-dependent probe amplification, regular and systematic ultrasonic monitoring, and placental study, can accurately assess the prognosis and guide the management of the affected pregnancy.

Contribution of uniparental disomy to fetal growth restriction: a whole-exome sequencing series in a prenatal setting.

Fetal growth restriction (FGR), a leading cause of perinatal morbidity and mortality, is caused by fetal, maternal, and placental factors. Uniparental disomy (UPD) is a rare condition that leads to imprinting effects, low-level mosaic aneuploidies and homozygosity for pathogenic variants. In the present study, UPD events were detected in 5 women with FGR by trio exome sequencing (trio-WES) of a cohort of 150 FGR cases. Furthermore, noninvasive prenatal testing results of the 5 patients revealed a high risk of rare autosomal trisomy. Trio-WES showed no copy-number variations (CNVs) or nondisease-causing mutations associated with FGR. Among the 5 women with FGR, two showed gene imprinting, and two exhibited confined placental mosaicism (CPM) by copy number variant sequencing (CNV-seq). The present study showed that in FGR patients with UPD, the detection of imprinted genes and CPM could enhance the genetic diagnosis of FGR.

Genetic analysis of chorionic villus tissues in early missed abortions.

Chromosomal abnormalities are the most common etiology of early spontaneous miscarriage. However, traditional karyotyping of chorionic villus samples (CVSs) is limited by cell culture and its low resolution. The objective of our study was to investigate the efficiency of molecular karyotyping technology for genetic diagnosis of early missed abortion tissues. Chromosome analysis of 1191 abortion CVSs in early pregnancy was conducted from August 2016 to June 2021; 463 cases were conducted via copy-number variations sequencing (CNV-seq)/quantitative fluorescent-polymerase chain reaction (QF-PCR) and 728 cases were conducted using SNP array. Clinically significant CNVs of CVSs were identified to clarify the cause of miscarriage and to guide the couples' subsequent pregnancies. Among these, 31 cases with significant maternal cell contamination were removed from the study. Among the remaining 1160 samples, 751 cases (64.7%) with genetic abnormalities were identified, of which, 531 (45.8%) were single aneuploidies, 31 (2.7%) were multiple aneuploidies, 50 (4.3%) were polyploidies, 54 (4.7%) were partial aneuploidies, 77 (6.6%) had submicroscopic CNVs (including 25 with clinically significant CNVs and 52 had variants of uncertain significance), and 8 cases (0.7%) were uniparental disomies. Our study suggests that both SNP array and CNV-seq/QF-PCR are reliable, robust, and high-resolution technologies for genetic diagnosis of miscarriage.

Genetic and ultrasonographic analyses of fetuses with 1q21.1q21.2 microdeletion/microduplication: a retrospective study.

BACKGROUND: 1q21.1q21.2 microdeletions/microduplications are rare and incompletely penetrant genetic mutations, and only a few reports regarding their prenatal diagnosis are currently available. Here, we analyzed the ultrasonographic phenotypic characteristics of fetuses with these mutations to improve the understanding, diagnosis, and screening of these mutations during gestation. METHODS: We retrospectively analyzed 8700 cases of pregnant women who underwent invasive prenatal screening by karyotyping and chromosomal microarray analysis (CMA) between November 2016 and November 2021. RESULTS: CMA revealed copy number changes in the 1q21.1q21.2 region of eleven fetuses, of which five had microdeletions and six had microduplications. These eleven fetuses exhibited variable ultrasonographic phenotypes. Of the five fetuses with the microdeletion, one exhibited a right-dominant heart, permanent right umbilical vein, and mild tricuspid regurgitation, another showed thickened nuchal translucency, and the remaining three had normal ultrasound phenotypes. Two of the six cases with 1q21.1q21.2 microduplication had structural malformations; one of them had a bilateral subependymal cyst, neck mass, and enlarged cardiothoracic ratio, while the other had right ventricular hypoplasia. Of the remaining four cases, two exhibited nasal bone dysplasia, one showed measurement slower than that during menopause and mild tricuspid regurgitation, and another did not show any notable abnormality in ultrasound examination. Among the eleven cases of 1q21.1q21.2 microdeletion/microduplication, only the parents of two fetuses underwent pedigree verification. The parents of these two fetuses with 1q21.1q21.2 microdeletion syndrome chose to continue the pregnancy, and all aspects of postnatal follow-up were normal. The parents of the other nine fetuses refused pedigree verification; of these cases, four cases terminated, and five cases continued the pregnancies. The five continued pregnancies were followed up after birth; no abnormalities were found. CONCLUSIONS: Fetuses with 1q21.1q21.2 microdeletion/microduplication show different ultrasound characteristics and may have congenital heart disease, thickened nuchal translucency, and nasal bone dysplasia or show no notable abnormalities in an ultrasound examination. Our study highlights that CMA as a powerful diagnostic tool for these diseases can provide an accurate genetic diagnosis, while improving prenatal diagnosis standards.

Molecular analysis and prenatal diagnosis of seven Chinese families with genetic epilepsy.

Introduction: Genetic epilepsy is a large group of clinically and genetically heterogeneous neurological disorders characterized by recurrent seizures, which have a clear association with genetic defects. In this study, we have recruited seven families from China with neurodevelopmental abnormalities in which epilepsy was a predominant manifestation, aiming to elucidate the underlying causes and make a precise diagnosis for the cases. Methods: Whole-exome sequencing (WES) combined with Sanger sequencing was used to identify the causative variants associated with the diseases in addition to essential imaging and biomedical examination. Results: A gross intragenic deletion detected in MFSD8 was investigated via gap-polymerase chain reaction (PCR), real-time quantitative PCR (qPCR), and mRNA sequence analysis. We identified 11 variants in seven genes (ALDH7A1, CDKL5, PCDH19, QARS1, POLG, GRIN2A, and MFSD8) responsible for genetic epilepsy in the seven families, respectively. A total of six variants (c.1408T>G in ALDH7A1, c.1994_1997del in CDKL5, c.794G>A in QARS1, c.2453C>T in GRIN2A, and c.217dup and c.863+995_998+1480del in MFSD8) have not yet been reported to be associated with diseases and were all evaluated to be pathogenic or likely pathogenic according to the American College of Medical Genetics and Genomics (ACMG) guidelines. Methods: Based on the molecular findings, we have associated the intragenic deletion in MFSD8 with the mutagenesis mechanism of Alu-mediated genomic rearrangements for the first time and provided genetic counseling, medical suggestions, and prenatal diagnosis for the families. In conclusion, molecular diagnosis is crucial to obtain improved medical outcomes and recurrence risk evaluation for genetic epilepsy.

Prenatal genetic analysis of fetal aberrant right subclavian artery with or without additional ultrasound anomalies in a third level referral center.

To evaluate the correlation between chromosomal abnormalities and fetal aberrant right subclavian artery (ARSA) with or without additional ultrasound anomalies (UAs). A total of 340 fetuses diagnosed with ARSA by ultrasound between December, 2015, and July, 2021, were included. All cases were subdivided into three groups: (A) 121 (35.6%) cases with isolated ARSA, (B) 91 (26.8%) cases with soft markers, and (C) 128 (37.6%) cases complicated with other UAs. Invasive testing was performed via amniotic fluid or cord blood karyotyping and chromosomal microarray analysis (CMA) in parallel, and pregnancy outcomes were followed. Karyotype abnormalities were identified in 18/340 (5.3%) patients. Karyotype abnormalities in Groups A, B, and C were 0/121 (0.0%), 7/91 (7.7%), and 11/128 (8.6%), respectively. CMA abnormalities with clinically significant variants were detected in 37/340 (10.9%) cases, of which 22q11.2 deletion syndrome and trisomy 21 accounted for 48.6% (18/37). The overall abnormal CMA with clinically significant variant detection rates in Groups A, B, and C were 3/121(2.5%), 13/91 (14.3%), and 21/128 (16.4%), respectively. There were significant difference in clinically significant CMA anomalies detection rate between Groups A and C (p < 0.05), as well as Groups A and B (p < 0.05). Comparing CMA to karyotyping showed a clinically significant incremental yield in Group C (7.8%, 10/128) compared to Groups A (2.5%, 3/121) and B (6.6%, 6/91) (p > 0.05). Fetal ARSA with additional UAs, concurred with cardiac and extra-cardiac anomalies, constitutes a high-risk factor for chromosomal aberrations, especially for pathogenic or likely pathogenic copy number variants.

Efficiency of expanded noninvasive prenatal testing in the detection of fetal subchromosomal microdeletion and microduplication in a cohort of 31,256 single pregnancies.

Noninvasive prenatal testing (NIPT) is widely used to screen for common fetal chromosomal aneuploidies. However, the ability of NIPT-Plus to detect copy number variation (CNV) is debatable. Accordingly, we assessed the efficiency of NIPT-Plus to detect clinically significant fetal CNV. We performed a prospective analysis of 31,260 singleton pregnancies, included from June 2017 to December 2020. Cell-free fetal DNA was directly sequenced using the semiconductor sequencing platform for women with high-risk CNV with clinically significant results. Fetal karyotyping and chromosomal microarray analysis (or next-generation sequencing) are recommended for invasive diagnostic procedures. Women at low risk with no other abnormal results continued their pregnancies. We analyzed the expanded NIPT results, diagnostic test results, and follow-up information to evaluate its performance in detecting fetal CNV. Of the 31,260 pregnant women who received NIPT-Plus, 31,256 cases were tested successfully, a high risk of clinically significant CNV was detected in 221 cases (0.71%); 18 women refused further diagnosis; 203 women underwent invasive prenatal diagnosis; and 78 true positive cases and 125 false positive cases, with an overall positive predictive value (PPV) of 38.42% and a false positive rate of 0.40%. For known microdeletion/microduplication syndromes (n = 27), the PPVs were 75% DiGeorge syndrome (DGS), 80% 22q11.22 microduplication, 50% Prader-Willi syndrome, and 50% cri-du-chat. For the remaining clinically significant fetal CNVs (n = 175), the combined PPVs were 46.5% (CNVs > 10 Mb) and 28.57% (CNVs ≤ 10 Mb). NIPT-Plus screening for CNV has certain clinical value. NIPT-Plus yielded relatively high PPVs for 22q11.2 microduplication syndrome and DGS, and low to moderate PPVs for other CNVs.

Positive predictive value of noninvasive prenatal testing for sex chromosome abnormalities.

BACKGROUND: Early and intermediate serological screening cannot detect sex chromosome abnormalities. Currently, noninvasive prenatal testing (NIPT) is the only procedure available for screening such disorders; however, its use is controversial. METHODS AND RESULTS: A total of 47,855 pregnant women underwent NIPT at our referral center from January 2014 to December 2020. Of the 314 patients with a positive NIPT indicating sex chromosome abnormalities, 260 were screened via karyotype analysis and single nucleotide polymorphism (SNP) array after amniotic fluid extraction; 96 cases were confirmed. Karyotype analysis and SNP array were consistent in the diagnosis of 88 out of the 96 fetuses. The positive predictive value (PPV) for sex chromosome abnormalities was found to be 36.9%. The PPV in patients aged 30-34 years was significantly higher than that in patients aged < 30 years. No statistically significant difference was observed on the PPV among patients with or without previous adverse pregnancy outcomes. Moreover, 83 women carrying fetuses were diagnosed with a sex chromosome abnormality terminated their pregnancy. CONCLUSIONS: Improvements in detection and analytical technologies are needed to increase the accuracy of sex chromosome abnormalities detection. Pregnant women with a positive NIPT for these abnormalities may require invasive diagnostic procedures such as karyotype analysis and SNP array for better genetic counseling.

Single nucleotide polymorphism array in genetic evaluation of fetal ultrasound abnormalities: a retrospective follow-up study.

Fetal ultrasound abnormalities may be complicated by cognitive dysfunction or developmental retardation, and ultrasonography cannot detect these problems; therefore, chromosome detection is required in fetuses with ultrasound abnormalities. To examine the effectiveness of single nucleotide polymorphism (SNP) array in genetic diagnosis of fetal ultrasound abnormalities, the prenatal samples of 805 pregnant women with fetal ultrasound abnormalities were collected for SNP array and karyotyping analysis. A 95.5% percentage of normal karyotypes and 4.5% percentage of abnormal karyotypes were observed, and aneuploidy was detected in 28 fetuses with abnormal karyotypes. SNP array identified 89 positives, including 55 cases (6.8%) with pathogenic copy number variation (CNVs) and 34 (4.2%) with variants of unknown significance (VOUS). In addition to 36 cases showing consistent results with karyotyping, SNP array detected 19 additional cases with pathogenic CNVs, including microdeletion/microduplication syndromes in 18 cases and uniparental disomy in one case. The detection rate of pathogenic CNVs was highest in fetuses with structural abnormalities of multiple systems complicated by non-structural abnormalities (13.7%) and lowest in those with structural abnormalities of a single system (4.2%). Presence of pathogenic CNVs was 12.2% in fetuses with structural abnormalities in the urinary system, followed by in the skeletal system (10.3%), while no pathogenic CNVs were identified in fetuses with structural abnormalities in the head and face, the respiratory system or the digestive system. An 89.6% follow-up rate was seen in the study sample, and 55 fetuses with pathogenic CNVs identified by SNP array were all given induction of labor. Our data demonstrate that SNP array improves the detection of genetics aberrations in fetuses with prenatal ultrasound abnormality relative to karyotyping.

APA scoring system: a novel predictive model based on risk factors of pregnancy loss for recurrent spontaneous abortion patients.

The aim of this study was to analyse the risk factors of pregnancy loss of patients with recurrent spontaneous abortion (RSA) and develop a scoring system to predict RSA. Clinical data of 242 cases, with RSA who were treated at Fujian Provincial Maternity and Children's Hospital, were selected. The factors of pregnancy loss for RSA patients were evaluated by univariate and multivariate analyses. There were 242 RSA patients, of whom 34 (14.0%) developed pregnancy loss. A multivariate analysis showed the following adverse risk factors for RSA: antinuclear antibody spectrum, protein s deficiency and antiphospholipid antibodies. The pregnancy loss rates of antinuclear antibody spectrum group, protein S deficiency group and antiphospholipid antibodies group were 25.0%, 22.5% and 19.4%, respectively. Each of these factors contributed 1 point to the risk score. The pregnancy loss rates were 6.3%, 24.6%, 50% for the low-, intermediate- and high-risk categories, respectively (p < .001). The area under the receiver operating characteristic curve for the score of RSA was .733. Our findings suggest that this validated and simple scoring system could accurately predict the risk of pregnancy loss of RSA patients. The score might be helpful in the selection of risk-adapted interventions to decrease the incidence. Impact StatementWhat is already known on this subject? The live birth rate increases to 80%-90% after anticoagulant and/or immunosuppressive treatment in patients with RSA. However, there is still a high rate of re-abortion even after active treatment.What do the results of this study add? Antinuclear antibody spectrum, protein s deficiency and antiphospholipid antibodies were independent risk factors for pregnancy loss. A novel predictive model based on these factors was then established and validated.What are the implications of these findings for clinical practice and/or further research? The newly developed score might be helpful in the selection of risk-adapted interventions to decrease the incidence. For patients in the intermediate-risk and high-risk groups, we should conduct more targeted studies and formulate corresponding therapies to improve the success rate of treatment.

[Study on clinical features and diagnostic methods of prenatal Wolf-Hirschhorn syndrome].

OBJECTIVE: To investigate the clinical features of fetuses with Wolf-Hirschhorn syndrome(WHS) and explore the diagnostic methods and prenatal ultrasound characteristics and provide evidence for prenatal genetic counseling. METHODS: We retrospectively analyzed 5 cases of WHS fetuses diagnosed from March 2016 to February 2020, and analyzed the results of chromosomal karyotype analysis and chromosomal microarray analysis (CMA) of the fetuses. RESULTS: Five cases of WHS were detected by CMA, four cases were detected by karyotype analysis. Prenatal ultrasound revealed 4 abnormalities, of which 3 had intrauterine growth restriction, and only 1 had abnormalities of the maxillofacial region. The sequence of the fragments was 4p16.3p16.1 with a loss of 6.5 Mb, 4p16.3p15.32 with a loss of 15.6 Mb combined with 2p25.3 increased by 906kb, 4p16.3p15.31 with a loss of 20.4 Mb, 4p16.p15.1 with a loss of 35 Mb and 4p16.3p14 with a loss of 37 Mb. CONCLUSION: Fetal growth restriction may be one of the early manifestations of WHS. Absence of fetal facial abnormality by prenatal ultrasound screening cannot exclude WHS. Karyotype analysis may miss the diagnosis of WHS, while combined CMA techniques can improve the diagnostic accuracy.

Performance of Chromosomal Microarray Analysis for Detection of Copy Number Variations in Fetal Echogenic Bowel.

BACKGROUND: Fetal echogenic bowel (FEB) is associated with an increased risk of poor pregnant outcomes; however, karyotyping fails to detect copy number variations (CNVs) in FEB. This study aimed to evaluate the performance of chromosomal microarray analysis (CMA) for detection of FEB. METHODS: The medical records of 147 pregnant women with FEB recruited during December 2015 to December 2018 were retrospectively reviewed, and prenatal samples were collected for karyotyping and CMA. The detection of chromosomal abnormality was compared between karyotyping and CMA. RESULTS: Karyotyping identified eight cases with abnormal karyotypes (5.44% prevalence), including four fetuses with pathogenic aneuploidy, three with chromosome polymorphism and one with balanced chromosome translocation. CMA identified 13 abnormal CNVs (8.84% prevalence), including 4 fetuses with pathogenic aneuploidy as detected by karyotyping and 9 additional CNVs with normal karyotypes; however, CMA failed to detect chromosome polymorphism and balanced chromosome translocation. In fetuses with isolated FEB, no cases presented pathogenic findings and CMA detected two cases with variants of uncertain significance (VOUS). In cases presenting FEB along with other ultrasound abnormalities, CMA detected three cases with pathogenic CNVs and four cases with VOUS in addition to four cases with aneuploidy. There was no significant difference in the detection of abnormal CNVs between the fetuses with echogenic bowel alone and along with other ultrasound abnormalities (10% vs 8.67%, P > 0.05). Except 9 fetuses lost to the follow-up, the other 138 fetuses with echogenic bowel were successfully followed up. Pregnancy was terminated in 5 fetuses with chromosomal abnormality, 2 with pathogenic CNVs and 1 with VOUS, and other 16 with normal karyotypes and CMA findings but showing ultrasound abnormalities or multiple malformations. CONCLUSION: Isolated FEB is associated with a good prognosis, and a satisfactory pregnant outcome is expected for fetuses with echogenic bowel that are negative for chromosomal anomalies and other severe structure abnormalities. CMA shows an important value in the genetic diagnosis of FEB. As a supplement to karyotyping, CMA may improve the accuracy of prenatal diagnosis of fetal intestinal malformations in pregnant women with FEB.

[Value of copy number variation analysis and chromosomal karyotyping for the diagnosis of children with intellectual disability/developmental delay].

OBJECTIVE: To assess the value of copy number variations (CNVs) and chromosomal karyotyping analysis for patients with intellectual disability/developmental delay (ID/DD). METHODS: Chromosomal karyotype analysis was applied to 530 children diagnosed with ID/DD. Single nucleotide polymorphism array (SNP-array) was further applied for 120 children with unknown etiology. RESULTS: Among the 530 children with ID/DD, 104 (19.62%) were detected with chromosomal abnormalities. For the 120 children analyzed by SNP-array, 44 (36.67%) were detected with CNVs, among which 20 were predicted as pathogenic, 6 as likely pathogenic, 10 as variants of unknown significance, 7 as likely benign,and 1 as loss of heterozygosity. CONCLUSION: SNP-array can facilitate delineation of the etiology of patients with ID/DD, which may provide a basis for their prognosis, consultation and clinical intervention.

Detection of copy number variation associated with ventriculomegaly in fetuses using single nucleotide polymorphism arrays.

Etiopathogenesis of fetal ventriculomegaly is poorly understood. Associations between fetal isolated ventriculomegaly and copy number variations (CNVs) have been previously described. We investigated the correlations between fetal ventriculomegaly-with or without other ultrasound anomalies-and chromosome abnormalities. 222 fetuses were divided into four groups: (I) 103 (46.4%) cases with isolated ventriculomegaly, (II) 41 (18.5%) cases accompanied by soft markers, (III) 33 (14.9%) cases complicated with central nervous system (CNS) anomalies, and (IV) 45 (20.3%) cases with accompanying anomalies. Karyotyping and single nucleotide polymorphism (SNP) array were used in parallel. Karyotype abnormalities were identified in 15/222 (6.8%) cases. Karyotype abnormalities in group I, II, III, and IV were 4/103 (3.9%), 2/41 (4.9%), 4/33 (12.1%), and 5/45 (11.1%), respectively. Concerning the SNP array analysis results, 31/222 (14.0%) were CNVs, CNVs in groups I, II, III, and IV were 11/103 (10.7%), 6/41 (14.6%), 9/33 (27.3%), and 5/45 fetuses (11.1%), respectively. Detections of clinical significant CNVs were higher in non-isolated ventriculomegaly than in isolated ventriculomegaly (16.81% vs 10.7%, P = 0.19). SNP arrays can effectively identify CNVs in fetuses with ventriculomegaly and increase the abnormal chromosomal detection rate by approximately 7.2%, especially ventriculomegaly accompanied by CNS anomalies.

Prenatal diagnosis of PLP1 duplication by single nucleotide polymorphism array in a family with Pelizaeus-Merzbacher disease.

A family with a history of Pelizaeus-Merzbacher disease (PMD) received prenatal diagnosis of PLP1 gene duplication in a fetus using a single nucleotide polymorphism (SNP) array. A 27-year-old pregnant woman was referred for genetic counseling due to her four-year-old son being diagnosed with a suspected classic type of PMD. Amniocentesis was performed at 18 and 3/7 weeks of gestation, and the SNP array was carried out on DNA from the mother, her affected son, and fetus, then further confirmed by multiplex ligation-dependent probe amplification (MLPA). Cytogenetic analysis of the fetus showed 46,XY. SNP array analysis revealed that the male fetus did not carry PLP1 gene duplication but the affected boy did, and the mother was a carrier for the duplication of the PLP1 gene. All SNP array results were further confirmed by MLPA. SNP array and MLPA analyses of peripheral blood verified the nonduplication of the PLP1 gene in the infant after birth. At present, the child (without PLP1 duplication) is developing normally. This study preliminarily suggests that SNP array is a sensitive and accurate technology for identifying PLP1 duplication and is feasible for reliable diagnosis, including for the prenatal diagnosis of PMD resulting from PLP1 duplication.

Prenatal diagnosis and molecular cytogenetic identification of small supernumerary marker chromosomes: analysis of three prenatal cases using chromosome microarray analysis.

Small supernumerary marker chromosomes cannot be accurately identified by G-banding, and the related phenotypes vary greatly. It is essential to specify the origin, size, and gene content of marker chromosomes using molecular cytogenetic techniques. Herein, three fetuses with de novo marker chromosomes were initially identified by G-banding. Single nucleotide polymorphism array and fluorescence in situ hybridization were performed to characterize the origins of the marker chromosomes. The karyotypes of the three fetuses were 47,XY,+mar, 46,X,+mar[32]/45,X[68], and 45,X[62]/46,X,+mar[9]. In case 1, the karyotype was confirmed as 47,XY,+ idic(22)(q11.2). Therefore, the sSMC originated from chromosome 22 and was associated with cat eye syndrome. In case 2, the marker chromosome derived from ring chromosome X, and the karyotype was interpreted as 45,X[68]/46,X,+r(X)(p11.1q21.31)[32]. Meanwhile, the karyotype of case 3 was defined as 45,X[62]/46,X,idic(Y)(q11.2) and the marker chromosome originated from chromosome Y. Case 1 continued the pregnancy, whereas the other two pregnancies underwent elective termination. The detailed characterization of marker chromosomes can facilitate informed decision making, prevent uncertainty, and provide proper prognostic assessments. Our findings emphasize the importance for combining cytogenetic and molecular genetic techniques in marker chromosome characterization.

Vaginal Microbiota Diversity of Patients with Embryonic Miscarriage by Using 16S rDNA High-Throughput Sequencing.

Embryonic miscarriage severely affects the life quality and physical and mental state of pregnant women. However, the detailed mechanism underlying embryonic miscarriage is not fully understood. This study is aimed at analyzing embryonic miscarriage. We collected samples from 25 normal pregnant women and 25 embryonic miscarriage patients of similar age to analyze microbiota isolated from the vagina. Crude examination of the vagina isolates showed that compared with the control group, 80% of the embryonic miscarriage group contained a significantly lower number of Lactobacillus, the major healthy microbe in the vagina. Furthermore, the levels of Th1 and Th2 secreted cytokine interleukin 2 (IL-2) and interleukin10 (IL-10), respectively, were examined. Results showed that the IL2 level was higher, and IL10 level was lower in the embryonic miscarriage group than in the control group, whereas the IL2/IL10 level was higher in the embryonic miscarriage group than in the control group. This finding suggested that the immune response was suppressed in the embryonic miscarriage group. To further dissect the microbiota of the vagina in the two groups, 16S rDNA sequencing was performed. Bioinformatics analysis showed that 1096 and 998 overlapped operational taxonomic units were identified from the embryonic miscarriage and control groups, respectively. At the genus level, the relative abundance of Fam_Finegoldia, Lac_Coprococcus_3, and Lac_Roseburia significantly differed in the embryonic miscarriage group. Overall, our analyses provided potential biomarkers for embryonic miscarriage and elucidated the causative relationship between microbiota and immune responses and may enable the possible diagnosis and therapeutics of early pregnancy loss.

Molecular characterization of thalassemia and hemoglobinopathy in Southeastern China.

Thalassemia and hemoglobinopathy are two common inherited disorders, which are highly prevalent in southern China. However, there is little knowledge on the genotypes of thalassemia and hemoglobinopathy in Southeastern China. In this study, we present a large-scale genetic detection and molecular characterization of thalassemia and hemoglobinopathy in Fujian province, Southeastern China. A total of 189414 subjects screened for thalassemia were recruited, and the hemoglobin components and levels were investigated. Furthermore, suspected common thalassemia was identified, and the suspected rare forms of common thalassemias and hemoglobinopathy were detected. Among the total subjects screened, the overall prevalence of thalassemia and hemoglobinopathy was 6.8% and 0.26%, and rare α-thalassemia genotypes HKαα, -THAI/αα and -α27.6/αα, and novel ß-thalassemia gene mutations CD90(G → T) and IVS-I-110(G > A) were identified. Additionally, Hb Q-Thailand hemoglobinopathy and five other types of hemoglobinopathies (Hb New York, Hb J-Bangkok, Hb G-Taipei, Hb G-Coushatta and Hb Maputo) were found. The results of this 10-year large-scale study demonstrate high prevalence of thalassemia with complicated gene mutations in Southeastern China, which provides valuable baseline data for genetic counseling and prenatal diagnosis. In addition to detection of common thalassemia genes, detection of rare thalassemia genotypes and hemoglobinopathies is recommended.

Molecular cytogenetic identification of small supernumerary marker chromosomes using chromosome microarray analysis.

BACKGROUND: This study aimed to evaluate the feasibility of chromosomal microarray analysis (CMA) in detecting the origin and structure of small supernumerary marker chromosomes (sSMCs) in prenatal and postnatal cases and to clarify sSMC-related genotype-phenotype correlations. RESULTS: Thirty-three cases carrying sSMCs were identified by banding cytogenetics. Of these cases, twenty-nine were first characterized by CMA and only two by FISH. The remaining two cases were excluded for their refusal to accept further examination. The chromosomal origins of twenty-two cases were successfully identified, in which pathogenetic copy number variations (PCNVs) were found in sixteen cases, four cases showed variants of uncertain significance (VOUS), one case showed benign CNVs, and one case showed probable PCNVs. For the nine cases with negative CMA results, only one of them contained centromere heterochromatin likely due to its normal phenotype, whereas reasons for the remaining eight cases were uncertain. We also found that CMA results indicating pathogenic abnormalities further affect the rate of pregnancy termination. CONCLUSIONS: This study showed that CMA combined with cytogenetic analysis is particularly effective in identifying sSMCs. However, in order to establish sSMC-related genotype-phenotype correlations, the inclusion of more sSMC cases will be necessary in future studies.