G-banding Karyotype Analysis Research Articles

Genetic analysis of a child with 18q terminal deletion and aortic regurgitation and a literature review

To explore the genetic characteristics of a child with 18q terminal deletion syndrome. Clinical data of a child presented at the Lianyungang Maternal and Child Health Care Hospital on July 20, 2023 was collected. Peripheral blood sample from the child was subjected to G-banded chromosomal karyotyping and chromosomal microarray analysis (CMA). Relevant literature was searched from CNKI, WanFang and PubMed databases over the past decade (from November 1, 2013 to November 1, 2023) using keywords including "18q-syndrome", "18q deletion syndrome" and "18q terminal deletion". This study was approved by the Lianyungang Maternal and Child Health Care Hospital (Ethics No. LYG-MER2021017). The child, a 4-year-and-6-month-old female, had manifested short stature, intellectual disability, distinctive facial features, aortic regurgitation, auditory canal atresia, and white matter lesions. She was found to have a karyotype of 46,XX,del(18)(q21), whilst the result of CMA was arr[GRCh37]18q21.33q23(60065821_77317445)×1. Both of her parents were found to have a normal karyotype. Literature review has retrieved 7 reports which involved 11 cases with a terminal 18q23 deletion. The phenotypes of cardiac abnormalities have been diverse, with pulmonary stenosis, atrial septal defect and ventricular septal defect being most common. The 18q terminal deletion probably underlay the multiple congenital anomalies and mental retardation in this child.

Prenatal diagnosis of a fetus with 15q11q13 complex duplication syndrome and a literature review

To explore the clinical features and genetic etiology of a fetus with 15q11q13 complex duplication syndrome. A fetus diagnosed with 15q11q13 duplication syndrome at Ningbo Women and Children's Hospital on April 19, 2023 was selected as the study subject. Clinical data was collected, and the fetus was subjected to invasive prenatal diagnosis including G-banded karyotyping and chromosomal microarray analysis (CMA). Following the discovery of chromosomal duplication, trio-whole exome sequencing was carried out to exclude single base variants and confirm the parental original of the duplication. Optical genome mapping was also performed to delineate the structural arrangement of the duplication. Relevant literature was searched in the PubMed, Wanfang Medical Network and CNKI databases using "15q11q13", "duplication", "hexasomy" and "Six fold repetition" as the key words from January 1, 2000 to August 1, 2023 for a review of previously reported 15q11q13 hexasomy cases. This study was approved by the Ningbo Women & Children's Hospital (Ethics No. EC2020-048). The fetus was found to have a mosaicism karyotype of 48,X?,+mar,+idic(15)(q13)[33]/47,X?,+idic(15)(q13)[17]. CMA and trio-WES have all shown a six-fold duplication in the PWS/AS critical region (PWACR) at 15q11.2q13.2 and quadruple duplication of 15q13.2q13.3 region, which have derived from its mother and formed supernumerary marker chromosomes (SMCs). Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the 15q11.2q13.2 sixfold duplication was classified as pathogenic, whilst the 15q13.2q13.3 quadruple duplication was classified as variant of uncertain significance. Literature search has identified 11 cases of 15q11q13 duplication involving hexasomy of the PWACR, with all cases showing mental retardation, language delay and hypotonia, and most of them also had motor retardation, epilepsy and mild facial dysmorphism. Hexasomy for the PWACR combined with tetrasomy of 15q13.2q13.3 probably underlay the left hand polydactyly, polyhydramnios and intrauterine growth retardation in this fetus.

The establishment of pulp polyp-derived mesenchymal stem cells with normal karyotype

Background/PurposePulp polyp is often eliminated as dental waste. Pulp polyp cells were reported to have high proliferation activity which might be comprised of stem cells. However, little has been known on the presence of stem cells in the pulp polyp. Moreover, pulp polyp cells might contain chromosomal abnormality. The present study was conducted to investigate the presence of pulp polyp stem cells, which could later be propagated and confirmed as normal/non-pathogenic cells using karyotype analysis. Materials and methodsCollected pulp polyps were minced, enzymatically digested, and cultured. Expression of mesenchymal stem cell (MSC) markers on pulp polyp cells were analyzed using flow cytometry. Multilineage differentiation capacity was assessed by culturing the cells in osteogenic, chondrogenic, and adipogenic differentiation media. Genomic stability of the cells was evaluated with G-banded and molecular karyotype analyses. ResultsPulp polyp cells appeared as fibroblasts-like cells. The cells were positive for cluster of differentiation (CD)105, CD90, and CD73, and negative for CD45, CD34, CD11b, CD19, and human leukocyte antigen (HLA)-DR. The cells were capable of osteogenic, chondrogenic, and adipogenic differentiation. G-banded karyotype analysis showed that there was no abnormality in the number or structure of chromosomes in pulp polyp-derived MSCs (PP-MSCs). Molecular karyotype analysis revealed that all copy number variations identified in PP-MSCs were not pathogenic. ConclusionPP-MSCs, which fulfill the minimal criteria for MSCs and are proven to have normal karyotype, have been successfully established. PP-MSCs might be a promising and safe candidate that can be considered for pulp-dentin complex regeneration.

Comparative analysis of the application with the combination of CMA and karyotype in routine and late amniocentesis.

This is a retrospective comparative study. We aimed to analyze the results of karyotype and chromosomal microarray analysis (CMA) of amniotic fluid across different gestational weeks and evaluate the clinical value in prenatal diagnosis, particularly in the late pregnancies. Samples from 580 pregnant women of 18-23weeks of gestation (mid-gestation group) and 196 pregnant women of 24-32weeks of gestation (late group) were performed both standard G-band karyotype analysis and CMA. Among the 580 pregnant women in the routine group, the most common indications were positive Down's screening (213/580, 36.7%), followed by advanced maternal age (196/580, 33.8%); while fetal structural anomalies on ultrasonography were the top reason for amniocentesis in the late group (56/196, 28.6%). In the routine group, the total detection rate was 12.1% (70/580), of which 4.1% (24/580) were identified by karyotype analysis and 11.2% (65/580) by CMA. The total detection rate was 15.3% (30/196) in the late group, of which 5.1% (10/196) were detected by karyotype analysis, and 14.3% (28/196) by CMA. Karyotype analysis and CMA are complementary in detecting chromosomal abnormalities. Amniotic cavity puncture in the karyotype analysis in 18-23weeks of gestation and 24-32weeks of gestation is safe and effective, more obvious effect on the latter.

Establishment of Canine Oral Mucosal Melanoma Cell Lines and Their Xenogeneic Animal Models.

Canine oral melanoma is the most prevalent malignant tumor in dogs and has a poor prognosis due to its high aggressiveness and high metastasis and recurrence rates. More research is needed into its treatment and to understand its pathogenic factors. In this study, we isolated a canine oral mucosal melanoma (COMM) cell line designated as COMM6605, which has now been stably passaged for more than 100 generations, with a successful monoclonal assay and a cell multiplication time of 22.2 h. G-banded karyotype analysis of the COMM6605 cell line revealed an abnormal chromosome count ranging from 45 to 74, with the identification of a double-armed chromosome as the characteristic marker chromosome of this cell line. The oral intralingual and dorsal subcutaneous implantation models of BALB/c-nu mice were successfully established; Melan-A (MLANA), S100 beta protein (S100β), PNL2, tyrosinase-related protein 1 (TRP1), and tyrosinase-related protein 2 (TRP2) were stably expressed positively in the canine oral tumor sections, tumor cell lines, and tumor sections of tumor-bearing mice. Sublines COMM6605-Luc-EGFP and COMM6605-Cherry were established through lentiviral transfection, with COMM6605-Luc-EGFP co-expressing firefly luciferase (Luc) and enhanced green fluorescent protein (EGFP) and COMM6605-Cherry expressing the Cherry fluorescent protein gene. The COMM6605-Luc-EGFP fluorescent cell subline was injected via the tail vein and caused lung and lymph node metastasis, as detected by mouse live imaging, which can be used as an animal model to simulate the latter steps of hematogenous spread during tumor metastasis. The canine oral melanoma cell line COMM6605 and two sublines isolated and characterized in this study can offer a valuable model for studying mucosal melanoma.

Evaluation the Application of Karyotype Analysis and Chromosome Microarray in Prenatal Diagnosis.

We aimed to compare the difference of the chromosomal abnormalities using karyotype analysis and chromosomal microarray (CMA) as well as to evaluate their application in different prenatal diagnosis indications. Overall, 3007 pregnant women with prenatal diagnosis indications from Medical Genetics Department of Linyi Women and Children's Health Care Hospital, who underwent standard G-banded karyotype analysis and CMA, were enrolled from 2018-2022. G-banded karyotype analysis and CMA were undergone simultaneously. All fetuses with genetic variants were enrolled for further analyzing. The frequency and differences of chromosomal abnormalities of the two methods were compared in different prenatal diagnosis indications groups. CMA improved 4.09% (123/3007) of genetic changes compared karyotype analysis. CMA is on par with karyotyping for detection of aneuploidies and gross unbalanced rearrangements. Serological screening and ultrasound abnormalities were the main indications of prenatal diagnosis. The detection rate of chromosomal abnormalities was highest in non-invasive prenatal testing (NIPT) abnormal group. In the ultrasound abnormality group, the detection rate of genetic variants in nuchal translucency (NT) increased group was higher than other subgroups and there was statistically significant difference in the detection rate of pCNVs. CMA can detect 5.57% (40/718) more genetic abnormalities in ultrasound abnormality group on the normal karyotype. CMA improved 0.67% (20/3007) of genetic changes with clinically significant compared karyotype, brought 3.42% (103/3007) of variants with uncertain significance (VOUS). CMA identified additional, clinically significant genetic variants on the basis of normal karyotype analysis, brought a proportion of unclear significant variants. All the pregnant women accepted amniocentesis should be informed about their characteristics of karyotype analysis and CMA by genetic counselors.

Frequency and characteristics of Y chromosome microdeletions and karyotypic abnormalities among 4 278 infertile male patients from southwest China

To determine the frequency and characteristics of AZF microdeletions of Y chromosome and karyotypic abnormalities among infertile male patients from southwest China. 4 278 infertile male patients treated at West China Second University Hospital of Sichuan University from September 2018 to July 2023 were selected as the study subjects. Results of Y chromosome microdeletion detection and G-banded karyotyping analysis were retrospectively reviewed. Clinical data of the patients were collected, which have included 2 048 patients with azoospermia, 1 536 patients with oligozoospermia, 310 patients with mild to moderate oligozoospermia, and 384 patients with infertility but normal sperm concentration. An abnormal karyotype was found in 213 (8.80%) of 2 421 patients who had undergone karyotyping analysis. The frequency of Y chromosome microdeletions was 9.86% (422/4 278), which had occurred in 10.4%, 13.28%, 0.97% and 0.52% of the cases with azoospermia, severe oligozoospermia, mild to moderate oligozoospermia, and infertility with normal sperm concentration, respectively. Y chromosome microdeletion detection and karyotyping analysis are crucial for assessing the cause of male infertility. Early diagnosis can facilitate the selection of reproductive methods.

Genetic analysis of a fetus with Pitt-Hopkins syndrome due to a 18q21.2q21.31 microdeletion

To carry out invasive prenatal diagnosis for a fetus with ultrasound-indicated agenesis of corpus callosum and explore its genetic etiology. A pregnant woman presented at the Affiliated Hospital of Putian College on December 16, 2022 was selected as the study subject. Amniotic fluid and peripheral blood samples from the fetus and the couple were collected. Conventional G-banded chromosomal karyotyping was carried out, and whole-genome copy number variation analysis was performed using single nucleotide polymorphism microarray (SNP-array). The karyotypes of the fetus and the couple were normal by the G-banding analysis. SNP-array analysis of the amniotic fluid sample revealed a 4.5 Mb microdeletion in the 18q21.2q21.31 region of the fetus. SNP-array analysis of peripheral blood samples from the couple did not find any abnormality. Through G-banded chromosomal karyotyping and SNP-array analysis, a fetus with 18q21.2q21.31 microdeletion was identified, which has conformed to the diagnosis of Pitt-Hopkins syndrome. Above finding has provided a basis for genetic counseling for the couple.

RanGAP1 maintains chromosome stability in limb bud mesenchymal cells during bone development

BackgroundBone development involves the rapid proliferation and differentiation of osteogenic lineage cells, which makes accurate chromosomal segregation crucial for ensuring cell proliferation and maintaining chromosomal stability. However, the mechanism underlying the maintenance of chromosome stability during the rapid proliferation and differentiation of Prx1-expressing limb bud mesenchymal cells into osteoblastic precursor cells remains unexplored. MethodsA transgenic mouse model of RanGAP1 knockout of limb and head mesenchymal progenitor cells was constructed to explore the impact of RanGAP1 deletion on bone development by histomorphology and immunostaining. Subsequently, G-banding karyotyping analysis and immunofluorescence staining were used to examine the effects of RanGAP1 deficiency on chromosome instability. Finally, the effects of RanGAP1 deficiency on chromothripsis and bone development signaling pathways were elucidated by whole-genome sequencing, RNA-sequencing, and qPCR. ResultsThe ablation of RanGAP1 in limb and head mesenchymal progenitor cells expressing Prx1 in mice resulted in embryonic lethality, severe cartilage and bone dysplasia, and complete loss of cranial vault formation. Moreover, RanGAP1 loss inhibited chondrogenic or osteogenic differentiation of mesenchymal stem cells (MSCs). Most importantly, we found that RanGAP1 loss in limb bud mesenchymal cells triggered missegregation of chromosomes, resulting in chromothripsis of chromosomes 1q and 14q, further inhibiting the expression of key genes involved in multiple bone development signaling pathways such as WNT, Hedgehog, TGF-β/BMP, and PI3K/AKT in the chromothripsis regions, ultimately disrupting skeletal development. ConclusionsOur results establish RanGAP1 as a critical regulator of bone development, as it supports this process by preserving chromosome stability in Prx1-expressing limb bud mesenchymal cells.

Establishment of a human ovarian clear cell carcinoma cell line mutant in PIK3CB but not PIK3CA

A human ovarian clear cell carcinoma cell line was established from a 46-year-old Japanese woman. That line, designated MTC-22, has proliferated continuously for over 6 months in conventional RPMI 1640 medium supplemented with 10% foetal bovine serum and has been passaged over 50 times. MTC-22 doubling-time is ~ 18 h, which is much shorter than most ovarian clear cell carcinoma lines reported to date. Morphologically, MTC-22 cells exhibit polygonal shapes and proliferate to form a monolayer in a jigsaw puzzle-like arrangement without contact inhibition. Ultrastructurally, cells exhibit numerous intracytoplasmic glycogen granules and well-developed mitochondria. G-band karyotype analysis indicated that cells have a complex karyotype close to tetraploid. We observed that the expression pattern of a series of ovarian carcinoma-related molecules in MTC-22 cells was identical to that seen in the patient’s tumour tissue. Notably, MTC-22 cells, and the patient’s carcinoma tissue, expressed low-sulphated keratan sulphate recognised by R-10G and 294-1B1 monoclonal antibodies, a hallmark of non-mucinous ovarian carcinoma, and particularly of clear cell ovarian carcinoma. Moreover, characteristic point mutations—one in ARID1A, which encodes the AT-rich interaction domain containing protein 1A, and the other in PIK3CB, which encodes the catalytic subunit of phosphoinositide 3-kinase—were seen in the patient’s tumour tissue and retained in MTC-22 cells. Collectively, these findings indicate that MTC-22 cells could serve as a valuable tool for investigating the pathophysiology of ovarian clear cell carcinoma, particularly that harbouring PIK3CB mutations, and for developing and validating new diagnostic and therapeutic approaches to this life-threatening malignancy.

Initial clinical and molecular investigation of 20q13.33 microdeletion with 17q25.3/14q32.31q32.33 microduplication in Chinese pediatric patients.

Limited research has been conducted regarding the elucidation of genotype-phenotype correlations within the 20q13.33 region. The genotype-phenotype association of 20q13.33 microdeletion remains inadequately understood. In the present study, two novel cases of 20q13.33 microdeletion were introduced, with the objective of enhancing understanding of the genotype-phenotype relationship. Two unrelated patients with various abnormal clinical phenotypes from Fujian province Southeast China were enrolled in the present study. Karyotype analysis and chromosomal microarray analysis (CMA) were performed to investigate chromosomal abnormalities and copy number variants. The results of high-resolution G-banding karyotype analysis elicited a 46,XY,der(20)add(20)(q13.3) in Patient 1. This patient exhibited various clinical manifestations, such as global developmental delay, intellectual disability, seizures, and other congenital diseases. Subsequently, a 1.0-Mb deletion was identified in the 20q13.33 region alongside a 5.2-Mb duplication in the 14q32.31q32.33 region. In Patient 2, CMA results revealed a 1.8-Mb deletion in the 20q13.33 region with a 4.8-Mb duplication of 17q25.3. The patient exhibited additional abnormal clinical features, including micropenis, congenital heart disease, and a distinctive crying pattern characterized by a crooked mouth. In the present study, for the first time, an investigation was conducted into two novel cases of 20q13.33 microdeletion with microduplications in the 17q25.3 and 14q32.31q32.33 regions in the Chinese population. The presence of micropenis may be attributed to the 20q13.33 microdeletion, potentially expanding the phenotypic spectrum associated with this deletion.

A rapid PCR-free next-generation sequencing method for comprehensive diagnosis of chromosome disease syndromes in prenatal samples.

The aim of this study is to investigate the application performance of rapid copy number variation sequencing (rCNV-seq) technology for the detection of chromosomal abnormalities during prenatal diagnosis. Samples were collected from 424 pregnant women who were at high-risk for noninvasive prenatal screening in Kunming Maternal and Child Care Hospital from January 2018 to May 2022. rCNV-seq technique was used to detect fetal chromosome abnormalities and compare the results with that of chromosomal karyotype analysis. The Result showed that 330 (77.83%, 330/424) cases indicated chromosomal abnormalities among 424 high-risk pregnant women who underwent rCNV-seq. Moreover, 94 (22.17%, 94/424) cases were discovered to have copy number variations. Among the 330 fetuses with chromosomal abnormalities, common autosomal aneuploidy was observed in 203 cases (47.87%, 203/424) and sex chromosome aneuploidy was observed in 91 cases (21.46%, 91/424). Moreover, the abnormalities in multiple chromosomes were discovered in 33 cases (7.78%, 33/424), and the rare autosomal aneuploidy was observed in 3 cases (0.71%, 3/424). There were 63 fetuses (14.86%, 63/424) with pathogenic CNVs among the 94 fetuses with variable copy numbers. Of the 245 pregnant women who voluntarily selected G-band karyotyping, 1 fetus with copy number variation had normal karyotype results, and the remaining women were consistent with rCNV-seq. Our study revealed that rCNV-seq has higher accuracy in detecting common trisomy and can also detect chromosomal microdeletions or microduplications that cannot be detected by G-banding karyotype analysis. There is no effective treatment for chromosomal diseases, so it is particularly important to prevent chromosomal diseases through genetic counseling and prenatal diagnosis of chromosomal diseases.

Prenatal diagnosis and genetic analysis of three fetuses with duodenal atresia or stenosis

To explore the genetic basis for three fetuses with duodenal atresia or stenosis detected by ultrasonography. Clinical data of three fetuses identified at the Women's Hospital Affiliated to Zhejiang University School of Medicine between January 2021 and August 2022 were collected. Umbilical cord blood and amniotic fluid samples of the fetuses and peripheral blood samples of their parents were collected and subjected to G-banded chromosomal karyotyping and single nucleotide polymorphism array (SNP array) analysis. Prenatal ultrasound of the three fetuses revealed duodenal atresia or stenosis. No karyotypic abnormality was detected, whilst SNP array has identified 1.4 ~ 1.9 Mb duplications at 17q12 in all of them, which were all predicted to be pathogenic copy number variations (CNVs). The 17q12 duplications probably underlay the duodenal atresia and stenosis in these fetuses, and chromosomal CNVs should be considered in duodenal atresia and stenosis.

JAK2 Kinase Fusion and Myeloid Involvement in Acute Lymphoblastic Leukemia

Introduction JAK2 fusion genes (FGs) are rare but can be found in various phenotypes of myeloid or lymphoid malignancies. Both in the 5th edition of the World Health Organization Classification of Haematolymphoid Tumors (WHO-HAEM5, PMID: 35732831) and the International Consensus Classification (ICC, PMID: 35767897), JAK2-FGs were included in the diagnostic entity of myeloid/lymphoid neoplasms with eosinophilia and tyrosine kinase gene fusions (MLN-TK or MLN-eo), and both suggest MLN-TK/eo as a priority diagnostic entity. It is highlighted in ICC that cases presenting as acute lymphoblastic leukemia (ALL) with M/LN-eo differ from de novo B-ALL and T-ALL in the involvement of myeloid cells. There is still a lack of research reports about how many JAK2-FG-positive ALL cases developed from M/LN-eo or had myeloid involvement. Methods A total of 21 ALL cases (Table 1) were enrolled in this study. The positive for JAK2-FGs were determined by G-banding karyotype analysis, transcriptome sequencing (RNA-seq; PMID: 34135310), reverse transcription PCR (RT-PCR), and interphase fluorescence in situ hybridization (I-FISH) with the JAK2 break-apart probe. Gene mutation analysis (PMID: 29932212) was also performed. According to whether there were FISH-JAK2 split signals in rod and lobed nuclear cells (Figure 1A), the cases were divided into My+ group (with myeloid involved) and My- group (without myeloid involved), respectively. Results Among these cases, there were 14 males and 7 females (M:F = 2:1); 15 B-ALL and 6 T-ALL cases; the median age was 22 years old (range 5-55). All cases were positive for JAK2-FGs in RNA-seq analysis, and all FGs were verified by RT-PCR and Sanger sequencing. A total of 16 JAK2 partner genes were detected (Table 1, Figure 1B/C), of which FNBP1, CDK5RAP2, GTF2I, and C14orf 93 have not been reported previously. All cases retained the complete kinase domain of the JAK2 gene, and 13 cases retained part or all of the JAK2 pseudo-kinase domain in their JAK2-FGs. Karyotype abnormalities were detected in 17 cases (81%), with 9p24 involved in 10 cases (48%), abnormalities other than 9p24 were observed in 7 cases, and karyotype was normal in 4 patients. FISH-JAK2 inspection showed split signals in 20 cases and showed negative results in case #21 who with a complex karyotype abnormality. Twelve cases (12/20=60%) showed JAK2 split signals in rotundum, rod, and lobed nuclei (Table 1, My+ group), suggesting both lymphoid and myeloid lineages were involved. We further investigated samples of 4 cases at the time of morphological complete remission after induction chemotherapy, of which the immunophenotype analysis was also negative for lymphoid blast cells. FISH-JAK2 inspection showed split signals accounting for 13%~79% of the nucleus, with split signals in the rod/lobed nucleus, and RT-PCR also confirmed abundant JAK2-FG transcripts in these samples. There were 8 B-ALL and 4 T-ALL cases in the My+ group, of which 2 T-ALL cases were also positive for STIL::TAL1 fusion, and 3 cases experienced eosinophilia during the course of the disease (Table 1). The 5 cases whose JAK2 partner genes were lymphoid development-related transcription factors (ETV6, PAX5) were all in the My- group. All My- cases and #21 had no documented eosinophilia. Among the 21 cases in this cohort, 13 had white blood cell (WBC) counts >50×10 9/L at diagnosis, and no significant hepatosplenomegaly. The total follow-up time was 2-89m, with a median overall survival (OS) time of 17m. Fourteen cases underwent allo-HSCT, and the median OS was 29.5m in the HSCT group and 9m in the non-HSCT group, respectively. The median OS was 15.5m in the My+ group and 29m in the My- group. The leukemia cells in these cases are prone to be in a high and rapid proliferation state, and they generally have a short OS and dismal prognosis. Conclusions Myeloid involvement accounted for 60% of JAK2-FG positive ALL and My+ cases had a worse prognosis and shorter OS than My- cases in this study. I-FISH inspection can be used as a method to determine whether there was myeloid involvement and provide valuable information for accurate analysis. The incidence of JAK2-FGs is low in ALL, but the fusion partners are diverse. This group of cases is more likely to have cryptic JAK2 translocations and with dismal prognosis. The phenotype of JAK2-FG malignancies is jointly determined by multiple factors under the influence of partner genes, accompanying fusion genes, and accompanying mutations.

Prenatal diagnosis of two fetuses with Xp22.31 microdeletion syndrome indicated by non-invasive prenatal testing

To assess the value of non-invasive prenatal testing (NIPT) for detecting fetal chromosomal microdeletion/microduplication syndromes by carrying out prenatal diagnoses for two fetuses with Xp22.31 microdeletion indicated by NIPT. Two pregnant women suspected for fetal Xp22.31 microdeletion syndrome who presented at Zaozhuang Maternal and Child Health Care Hospital on December 5, 2017 and October 15, 2020 were selected as the study subjects. Clinical data of the two women were collected, and peripheral venous blood samples were collected for NIPT testing. Amniotic fluid samples were taken for G-banding chromosomal karyotyping analysis and copy number variation sequencing (CNV-seq) for fetus 1, while G-banding chromosomal karyotyping and single nucleotide polymorphism microarray analysis (SNP array) were carried out for fetus 2. Peripheral venous blood samples of couple 1 were collected for CNV-seq to verify the origin of copy number variation . NIPT indicated that fetus 1 had harbored a 1.3 Mb deletion in the Xp22.31 region, while G-banding chromosomal karyotyping had found no abnormality. CNV-seq analysis verified the fetus to be seg[GRCh37]del(X)(p22.31)chrX:g.6800001_7940000del, with a 1.14 Mb deletion at Xp22.31, which was derived from its mother. NIPT indicated that fetus 2 had harbored a 1.54 Mb deletion in the Xp22.31 region, while G-banding chromosomal karyotyping had found no abnormality. SNP array analysis indicated arr[GRCh37]Xp22.31(6458940_8003247)×0, with a 1.54 Mb deletion in Xp22.31 region. NIPT not only has a good performance for detecting fetal trisomies 21, 18 and 13, but also has the potential for detecting chromosomal microdeletion/microduplications. For high risk fetuses indicated by NIPT, prenatal diagnosis needs to be carry out to verify the chromosomal abnormalities.

Retrospective analysis of cell-free fetal DNA prenatal testing of maternal peripheral blood

To assess the value of non-invasive prenatal testing (NIPT) for trisomy 21 (T21), trisomy 18 (T18), trisomy 13 (T13), sex chromosome aneuploidies, chromosomal microdeletions and microduplications using cell-free fetal DNA from peripheral blood samples of pregnant women. A total of 15 237 pregnant women who had undergone NIPT testing at the Maternity and Child Health Care Hospital of Zaozhuang from February 2015 to December 2021 were enrolled in this study. For those with a high risk by NIPT, amniotic fluid samples were collected for G-banding chromosomal karyotyping analysis and chromosomal microarray analysis to verify the consistency of NIPT with results of prenatal diagnosis. All of the women were followed up by telephone for pregnancy outcomes. Among the 15 237 pregnant women, 266 (1.75%) were detected with a high risk for fetal chromosomal abnormality were detected. Among these, 79 (29.7%) were at a high risk for T21, 26 (9.77%) were at a high risk for T18, 9 (3.38%) were at a high risk for T13, 74 (27.82%) were at a high risk for sex chromosome aneuploidies, 12 (4.51%) were at a high risk for other autosomal aneuploidies, and 66 (24.81%) were at a high risk for chromosomal microdeletions or microduplications. 217 women had accepted invasive prenatal diagnosis and respectively 50, 13, 1, 25, 1 and 18 were confirmed with T21, T18, T13, sex chromosome aneuploidies, autosomal aneuploidies and microdeletions/microduplications, and the positive predictive values were 75.76%, 68.42%, 11.11%, 40.32%, 10% and 35.29%, respectively. For 13 042 women (85.59%), the outcome of pregnancy were successfully followed up. During the follow-up, one false negative case of T21 was discovered. No false positive cases for T13 and T18 were found. NIPT has a sound performance for screening T13, T18 and T21, and is also valuable for screening other autosomal aneuploidies, sex chromosome aneuploidies and chromosomal microdeletions/microduplications.

Clinical features and genetic analysis of two fetuses with ring chromosome 21 mosaicism

To investigate the perinatal clinical phenotype and genetic characteristics of two fetuses with ring chromosome 21 mosaicisms. Two fetuses who were diagnosed at the Xiamen Maternal and Child Health Care Hospital in November 2021 were selected as the study subjects. Clinical data of the two fetuses were collected. Conventional G-banded karyotyping and chromosomal microarray analysis (CMA) were carried out for the fetuses and their parents. Prenatal ultrasonography of fetus 1 has revealed absence of nasal bone, ventricular septal defect, persistent left superior vena cava, and mild tricuspid regurgitation. Chromosomal karyotyping was 46,X?,dic r(21;21)(p12q22;q22p12)[41]/45,X?,-21[9]. CMA has revealed a 30.00 Mb quadruplication at 21q11.2q22.3 and a 3.00 Mb deletion at 21q22.3. For fetus 2, ultrasonography has revealed pointed echo of the nasal bone. The fetus was found to have a karyotype of 46,X?,r(21)(p12q22)[83]/45,X?,-21[14]/46,X?,dic r(21;21)(p12q22;q22p12)[3]. CMA has revealed a 5.10 Mb quadruplication at 21q22.12q22.3 and a 2.30 Mb deletion at 21q22.3. The perinatal phenotype of the two fetuses with ring chromosome 21 mosaicisms is related to the duplication of chromosomal segments near the breakpoints of the chromosomal deletions. The combined chromosomal karyotyping and CMA has enabled prenatal diagnosis and genetic counseling for these families.

Genetic analysis of a Chinese pedigree with 6q26q27 microduplication and 15q26.3 microdeletion

To explore the genetic basis for a Chinese pedigree with 6q26q27 microduplication and 15q26.3 microdeletion. A fetus with a 6q26q27 microduplication and a 15q26.3 microdeletion diagnosed at the First Affiliated Hospital of Wenzhou Medical University in January 2021 and members of its pedigree were selected as the study subject. Clinical data of the fetus was collected. The fetus and its parents were analyzed by G-banding karyotyping and chromosomal microarray analysis (CMA), and its maternal grandparents were also subjected to G-banding karyotype analysis. Prenatal ultrasound had indicated intrauterine growth retardation of the fetus, though no karyotypic abnormality was found with the amniotic fluid sample and blood samples from its pedigree members. CMA revealed that the fetus has carried a 6.6 Mb microduplication in 6q26q27 and a 1.9 Mb microdeletion in 15q26.3, and his mother also carried a 6.49 duplication and a 1.867 deletion in the same region. No anomaly was found with its father. The 6q26q27 microduplication and 15q26.3 microdeletion probably underlay the intrauterine growth retardation in this fetus.

A novel ADGRG2 truncating variant associated with X-linked obstructive azoospermia in a large Chinese pedigree.

In this study, we aimed to identify sterility-related variants in a Chinese pedigree with male infertility and to reveal the different phenotypes and intracytoplasmic sperm injection (ICSI) outcomes of the affected members. Physical examinations were performed on male patients. G-band karyotype analysis, copy number variation sequencing, and quantitative fluorescent PCR were conducted to detect common chromosomal disorders in the probands. Whole-exome sequencing and Sanger sequencing were applied to identify the pathogenic genes and the protein expression changes caused by the very mutation were identified by Western Blot in vitro. A novel nonsense mutation (c.908C > G: p.S303*) in the ADGRG2 was identified in all infertile male patients of the pedigree, which was inherited from their mothers. This variant was absent from the human genome databases. This mutation was also unexpectedly found in a male member with normal reproductive capability. Members with the mutation had different genitalia phenotypes, ranging from normal to dilated phenotypes of the vas deferens, spermatic veins and epididymis. There was a truncated ADGRG2 protein in vitro after mutation. Of the three patients' wives treated with ICSI, only one successfully gave birth. Our study is the first to report the c.908C > G: p.S303* mutation in the ADGRG2 in an X-linked azoospermia pedigree and is the first to report normal fertility in a member with this mutation, expanding the mutation spectrum and phenotype spectrum of this gene. In our study, ISCI had a success rate of only one-third in couples including men with azoospermia with this mutation.

Genetic analysis of a fetus with de novo 46,X,der(X)t(X;Y)(q26;q11)

To carry out prenatal genetic testing for a fetus with de novo 46,X,der(X)t(X;Y)(q26;q11). A pregnant woman who had visited the Birth Health Clinic of Lianyungang Maternal and Child Health Care Hospital on May 22, 2021 was selected as the study subject. Clinical data of the woman was collected. Peripheral blood samples of the woman and her husband and umbilical cord blood of the fetus were collected and subjected to conventional G-banded chromosomal karyotyping analysis. Fetal DNA was also extracted from amniotic fluid sample and subjected to chromosomal microarray analysis (CMA). For the pregnant women, ultrasonography at 25th gestational week had revealed permanent left superior vena cava and mild mitral and tricuspid regurgitation. G-banded karyotyping analysis showed that the pter-q11 segment of the fetal Y chromosome was connected to the Xq26 of the X chromosome, suggesting a Xq-Yq reciprocal translocation. No obvious chromosomal abnormality was found in the pregnant woman and her husband. The CMA results showed that there was approximately 21 Mb loss of heterozygosity at the end of the long arm of the fetal X chromosome [arr [hg19] Xq26.3q28(133912218_154941869)×1], and 42 Mb duplication at the end of the long arm of the Y chromosome [arr [hg19] Yq11.221qter(17405918_59032809)×1]. Combined with the search results of DGV, OMIM, DECIPHER, ClinGen and PubMed databases, and based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the deletion of arr[hg19] Xq26.3q28(133912218_154941869)×1 region was rated as pathogenic, and the duplication of arr[hg19] Yq11.221qter(17405918_59032809)×1 region was rated as variant of uncertain significance. The Xq-Yq reciprocal translocation probably underlay the ultrasonographic anomalies in this fetus, and may lead to premature ovarian insufficiency and developmental delay after birth. Combined G-banded karyotyping analysis and CMA can determine the type and origin of fetal chromosomal structural abnormalities as well as distinguish balanced and unbalanced translocations, which has important reference value for the ongoing pregnancy.