OBJECTIVE: To re-analyze a likely pathogenic variant in the Xq28 region identified by copy number variation sequencing (CNV-seq) through whole genome sequencing (WGS). METHODS: A fetus found to harbor a duplication in the Xq28 region by CNV-seq at Shengjing Hospital Affiliated to China Medical University in May 2023 was selected as the study subject. WGS was carried out for the fetus and its parents. Bioinformatic software was used to analyze the chromosomal structure and CNVs. Quantitative PCR (qPCR) was applied to determine the expression level of the MECP2 gene. This study has been approved by the Ethics Committee of Shengjing Hospital (Ethic No. 2013PS33K). RESULTS: A duplication (ChrX:153302641_153503563) and four breakpoints were identified on the X chromosome of the fetus' father. Bioinformatic analysis revealed that the duplicated region has involved exons 1 to 3 and part of the 5'-UTR of the MECP2 gene, which was inserted into the Xp11 region. Additionally, an inversion was detected in the Xp11 region adjacent to the duplicated segment. RT-PCR results showed normal level of MECP2 mRNA expression. The Xq28 duplication has not encompassed the entire MECP2 gene, nor disrupted its structure or altered its expression. CONCLUSION WGS has enabled more precise diagnosis of chromosomal structural variants and provided guidance for accurate genetic counseling for the affected families.
Humans ; Female ; Chromosomes, Human, X/genetics* ; DNA Copy Number Variations/genetics* ; Whole Genome Sequencing/methods* ; Methyl-CpG-Binding Protein 2/genetics* ; Pregnancy ; Male ; Adult

OBJECTIVE: To explore the molecular cytogenetic characteristics of three fetuses with psu idic(Y)(q11.22) using a combination of multiple methods. METHODS: A total of 11 000 pregnant women who underwent prenatal diagnosis at the Prenatal Diagnosis Center of Taizhou City from January 2019 to October 2024 were selected as the study subjects. Chromosome karyotype analysis (G-banding) and copy number variation analysis based on next-generation sequencing (NGS) were performed on the amniotic fluid/cord blood samples of the 11 000 fetuses. For cases suspected of Y chromosome abnormalities, C-banding and/or fluorescence in situ hybridization (FISH) and AZF microdeletion testing were additionally conducted. This study has been reviewed and approved by the Medical Ethics Committee of Taizhou Hospital, Zhejiang Province (Ethics No. KL20240860). RESULTS: Among the 11,000 prenatal samples undergoing concurrent karyotype and copy number variation analysis, two fetuses with 45,X/46,X,psu idic(Y)(q11.22) mosaicism and one fetus with 46,X,psu idic(Y)(q11.22) were detected. FISH detection indicated that approximately 66.7% of the cells in fetus 2 exhibited a dicentric Y chromosome, and the metaphase karyotype supported the presence of a pseudodicentric chromosome. AZF testing revealed complete deletion of the AZFb+AZFc regions in fetus 2 and fetus 3. CONCLUSION Conventional G-banding karyotype analysis for psu idic(Y)(q11.22) is prone to misdiagnosis or missed diagnosis. The combined application of chromosome karyotype analysis (G+C banding), copy number variation analysis, and FISH detection in clinical practice can accurately diagnose fetuses with psu idic(Y).
Humans ; Female ; Pregnancy ; Prenatal Diagnosis/methods* ; DNA Copy Number Variations/genetics* ; Adult ; Chromosomes, Human, Y/genetics* ; Karyotyping ; In Situ Hybridization, Fluorescence ; Cytogenetic Analysis/methods* ; Fetus ; High-Throughput Nucleotide Sequencing ; Male

OBJECTIVE: To investigate the X-chromosome inactivation (XCI) patterns and origin in four children with Rett syndrome (RTT), and to explore the genetic basis of their phenotypic variability. METHODS: Four pediatric RTT cases diagnosed at Northwest Women's and Children's Hospital between August 1, 2022 and October 31, 2024 were enrolled. Clinical data were collected, and whole exome sequencing (WES) and Sanger sequencing were performed on the children and their parents to identify pathogenic variants. XCI analysis and linkage studies were conducted to determine the origin of variants and assess skewed XCI. This study was approved by the Medical Ethics Committee of the Northwest Women's and Children's Hospital (Ethics No. 21-036). RESULTS: WES and Sanger sequencing revealed that the four children carried the following MECP2 (NM_001110792.2) variants. c.916C>T (p.Arg306Cys), c.842delG (p.G281Afs*20), c.763C>T (p.R255X), and c.686C>T (p.Pro229Leu). The c.916C>T variant was maternally inherited, while the other three were de novo. All four variants have been previously reported: c.916C>T, c.842delG, and c.763C>T were classified as pathogenic, whereas c.686C>T was deemed likely pathogenic. XCI analysis demonstrated skewed inactivation in child 2 and 3 and their mothers, with maternal X-chromosome recombination during gametogenesis observed in child 3. All variants were located on the maternal X chromosome. CONCLUSION Skewed XCI is a common pathogenic mechanism in MECP2-related RTT, and MECP2 variants may exhibit a maternal origin bias. Clinical evaluation should incorporate XCI status for comprehensive genetic analysis.
Child ; Humans ; Chromosomes, Human, X/genetics* ; Exome Sequencing ; Methyl-CpG-Binding Protein 2/genetics* ; Mutation ; Rett Syndrome/genetics* ; X Chromosome Inactivation/genetics*

OBJECTIVE: To explore the mechanism for the occurrence and phenotypic characteristics of Turner syndrome based on a prenatally diagnosed case of a mosaic karyotype containing double pseudo-isodicentric X chromosome and a review of relevant literature. METHODS: A fetus diagnosed with increased risk for trisomy 21 at the Provincial Hospital Affiliated to Shandong First Medical University in August 2023 was selected as the study subject. Clinical data of the fetus was collected. Following amniocentesis, chromosomal G-banding karyotype analysis and chromosomal microarray analysis (CMA) were carried out. This study has been approved by the Ethics Committee of the Hospital (Ethics No.: SWYX No. 2022-287). RESULTS: The early-trimester screening suggested a high risk of trisomy 21 (1/19), with free β-hCG of 116 ng/mL (MoM value 2.35), PAPP-A of 0.394 ng/mL (MoM value 0.12), and NT value of 1.3 mm, though no abnormality was found in the fetus at 19 weeks gestation. The karyotype of amniocyte was determined as 46,X,psu idic(X)(p11.21)[55]/45,X[27]/47,X,psu idic(X)(p11.21)×2[5]/46,XX[13]. CMA has yielded a result of arr[GRCh37] Xp22.33p11.21(168552_55585678)×1[0.67],Xp11.21q28(55703291_155233098)×3[0.5]. CONCLUSION Karyotypes of Turner syndrome are complex and diverse, and a rare 46,X,psu idic(X)(p11.21)[55]/45,X[27]/47,X,psu idic(X)(p11.21)×2[5]/46,XX[13] mosaic karyotype with double pseudo-isodicentric X chromosome has been identified. Literature review suggested that this karyotype may lead to phenotypic diversification and a risk of reduced sensitivity to hormone therapy.
Humans ; Turner Syndrome/diagnosis* ; Female ; Pregnancy ; Chromosomes, Human, X/genetics* ; Mosaicism ; Prenatal Diagnosis ; Karyotyping ; Adult ; Karyotype ; Amniocentesis

OBJECTIVE: To explore the clinical characteristics and genetic factors in four patients with Disorder of sex development (DSD). METHODS: Four patients who visited Tianjin Medical University General Hospital between January 2023 and January 2024, presenting with short stature, abnormal external genitalia, or infertility as their chief complaints, were selected as the study subjects. Clinical data were collected, and peripheral or umbilical cord blood samples were obtained for karyotyping analysis and low-depth whole-genome sequencing (CNV-seq). Quantitative fluorescence PCR (QF-PCR) was used to detect the sex-determining region Y (SRY) gene and azoospermia factor (AZF) on the Y chromosome, while fluorescence in situ hybridization (FISH) was employed to determine the location of the SRY gene. Whole exome sequencing (WES) was performed for genetic testing, and Sanger sequencing was used for familial validation of the candidate variants. The study procedure and protocol were approved by the Medical Ethics Committee of Tianjin Medical University General Hospital (Ethics No.: IRB2024-WZ-006). RESULTS: Case 1 had a karyotype of 45,X[22]/46,XY[8], with CNV-seq indicating a mosaic deletion of 7.44 Mb (copy number = 0.2) at Yp11.31-p11.2, a mosaic deletion of 5.32 Mb (copy number = 0.3) at Yq11.1-q11.221, and a deletion of 10.26 Mb (copy number = 0) at Yq11.221-q11.23. Y chromosome microdeletion analysis showed SRY and AZFa (+), AZFb+c (-). Case 2 had a karyotype of 45,X[12]/46,X,del(X)(q26.3)[18], with CNV-seq indicating a mosaic deletion of 132.62 Mb (copy number = 1.4) at Xp22.33-q26.3 and a deletion of 19.62 Mb (copy number = 1) at Xq26.3-q28. Case 3 had a karyotype of 46,XX, with CNV-seq showing two copies of the X chromosome and no Y chromosome. Y chromosome microdeletion analysis showed SRY (+) and AZFa+b+c (-), and FISH confirmed a translocation of the SRY gene to the terminal end of the short arm of the X chromosome. Case 4 had a karyotype of 46,XY, with CNV-seq showing one copy each of the X and Y chromosomes. Y chromosome microdeletion analysis showed SRY(+) and AZFa+b+c (+), and WES revealed a c.1103del variant in the AR gene (maternal origin), which was classified as a pathogenic variant based on the guidelines from the American College of Medical Genetics and Genomics (ACMG) (PVS1+PP1+PM2_Supporting). CONCLUSION The combined application of multiple detection techniques such as chromosomal karyotyping analysis, CNV-seq, QF-PCR, and WES can identify the genetic etiology of DSD patients, providing a basis for clinical consultation and treatment plan formulation.
Humans ; Male ; Female ; Chromosomes, Human, Y/genetics* ; Disorders of Sex Development/genetics* ; Sex-Determining Region Y Protein/genetics* ; Karyotyping ; In Situ Hybridization, Fluorescence ; Exome Sequencing ; Adult ; Child

Y chromosome microdeletions are an important cause of male infertility. At present, research on the Y chromosome is mainly focused on analyzing the loss of large segments of the azoospermia factor a/b/c (AZFa/b/c) gene, and few studies have reported the impact of unit point deletion in the AZF band on fertility. This study analyzed the effect of sperm quality after sY1192 loss in 116 patients. The sY1192-independent deletion accounted for 41.4% (48/116). Eight patterns were found in the deletions associated with sY1192. The rate of sperm detection was similar in the semen of patients with the independent sY1192 deletion and the combined sY1192 deletions (52.1% vs 50.0%). The patients with only sY1192 gene loss had a higher probability of sperm detection than the patients whose sY1192 gene locus existed, but other gene loci were lost (52.1% vs 32.0%). The hormone levels were similar in patients with sY1192 deletion alone and in those with sY1192 deletion and other types of microdeletions in the presence of the sY1192 locus. After multiple intracytoplasmic sperm injection (ICSI) attempts, the pregnancy rate of spouses of men with sY1192-independent deletions was similar to that of other types of microdeletions, but the fertilization and cleavage rates were higher. We observed that eight deletion patterns were observed for sY1192 microdeletions of AZFb/c, dominated by the independent deletion of sY1192. After ICSI, the fertilization rate and cleavage rate of the sY1192-independent microdeletion were higher than those of other Y chromosome microdeletion types, but there was no significant difference in pregnancy outcomes.
Humans ; Female ; Pregnancy ; Male ; Chromosomes, Human, Y/genetics* ; Adult ; Chromosome Deletion ; Pregnancy Outcome/genetics* ; Infertility, Male/genetics* ; Spermatozoa/physiology* ; Semen Analysis ; Sex Chromosome Disorders of Sex Development/genetics* ; Sperm Injections, Intracytoplasmic ; Azoospermia/genetics* ; Sex Chromosome Aberrations

Long non-coding RNAs (lncRNAs) reportedly function as important modulators of gene regulation and malignant processes in the development of human cancers. The lncRNA JPX is a novel molecular switch for X chromosome inactivation and differentially expressed JPX has exhibited certain clinical correlations in several cancers. Notably, JPX participates in cancer growth, metastasis, and chemoresistance, by acting as a competing endogenous RNA for microRNA, interacting with proteins, and regulating some specific signaling pathways. Moreover, JPX may serve as a potential biomarker and therapeutic target for the diagnosis, prognosis, and treatment of cancer. The present article summarizes our current understanding of the structure, expression, and function of JPX in malignant cancer processes and discusses its molecular mechanisms and potential applications in cancer biology and medicine.
Humans ; RNA, Long Noncoding/genetics* ; Neoplasms/genetics* ; MicroRNAs/genetics* ; Gene Expression Regulation ; X Chromosome Inactivation

Mosaic chromosomal alteration (mCA) is referred to as large-scale somatic mutations on chromosomes, which results in diverse karyotypes in body. The mCA is regarded as one of the phenotypes of aging. Studies have revealed its associations with many chronic diseases such as hematopoietic cancers and cardiovascular diseases, but its genetic basis (e.g. genetic susceptibility variants) is still under-investigated. This paper reviews GWAS studies for mCA on autosomal chromosomes and sex chromosomes [mosaic loss of the Y chromosome (mLOY) and mosaic loss of the X chromosome (mLOX)] based on large population, respectively. Most of the genetic susceptibility loci found in studies for autosomal mCA were associated with copy-neutral loss of heterozygosity. The study of sex chromosome mCA focused on mosaic loss mutations. The number of genetic susceptibility loci for mLOY was high (up to 156), but it was relatively less for mLOX.
Humans ; Male ; Genome-Wide Association Study/methods* ; Mosaicism ; Genetic Predisposition to Disease ; Chromosomes, Human, Y ; Mutation

Objective: To investigate the clinical phenotype and genetic characteristics of disorders of sex development (DSD) caused by Y chromosome copy number variant (CNV). Methods: A retrospective analysis was performed on 3 patients diagnosed with DSD caused by Y chromosome CNV admitted to the First Affiliated Hospital of Zhengzhou University from January, 2018 to September, 2022. Clinical data were collected. Clinical study and genetic test were performed by karyotyping, whole exome sequencing (WES), low coverage whole genome copy number variant sequencing (CNV-seq), fluorescence in situ hybridization (FISH) and gonadal biopsy. Results: The 3 children, aged 12, 9, 9 years, the social gender were all female, presented with short stature, gonadal dysplasia and normal female external genital. No other phenotypic abnormality was found except for case 1 with scoliosis. The karyotype of all cases were identified as 46, XY. No pathogenic vraiants were found by WES. CNV-seq determined that case 1 was 47, XYY,+Y(2.12) and case 2 was 46, XY,+Y(1.6). FISH concluded that the long arm of Y chromosome was broken and recombined near Yq11.2, and then produced a pseudodicentric chromosome idic(Y). The karyotype was reinterpreted as mos 47, X, idic(Y)(q11.23)×2(10)/46, X, idic(Y)(q11.23)(50) in case 1. The karyotype was redefined as 45, XO(6)/46, X, idic(Y)(q11.22)(23)/46, X, del(Y)(q11.22)(1) in case 2. 46, XY, -Y(mos) was found by CNV-seq in case 3, and the karyotype of 45, XO/46, XY was speculated. Conclusions: The clinical manifestations of children with DSD caused by Y chromosome CNV are short stature and gonadal dysgenesis. If there is an increase of Y chromosome CNV detected by CNV-seq, FISH is recommended to classify the structural variation of Y chromosome.
Humans ; Female ; DNA Copy Number Variations ; In Situ Hybridization, Fluorescence ; Retrospective Studies ; Chromosomes, Human, Y ; Turner Syndrome

OBJECTIVE: To explore the coincidence rate of G-banding karyotype analysis and fluorescence in situ hybridization (FISH) for the diagnosis of children with sex chromosome mosaicisms. METHODS: A retrospective analysis was carried out for 157 children with suspected sex chromosome abnormalities who had presented at Shenzhen Children's Hospital from April 2021 to May 2022. Interphase sex chromosome FISH and G-banding karyotyping results were collected. The coincidence rate of the two methods in children with sex chromosome mosaicisms was compared. RESULTS: The detection rates of G-banding karyotype analysis and FISH were 26.1% (41/157) and 22.9% (36/157) , respectively (P > 0.05). The results of G-banding karyotype analysis showed that 141 cases (89.8%) were in the sex chromosome homogeneity group, of which only 5 cases (3.5%) were inconsistent with the results of FISH. There were 16 cases (10.2%) in the sex chromosome mosaicism group, of which 11 cases (68.8%) were inconsistent with the results of FISH. There was a statistical difference between the two groups in the coincidence rate of the results of the two methods (P < 0.05). CONCLUSION No significant difference was found between G-banding karyotype analysis and FISH in the detection rate of chromosome abnormalities. The coincidence rate in the mosaicism group was lower than that in the homogeneity group, and the difference was statistically significant. The two methods should be combined for clinical diagnosis.
Humans ; Mosaicism ; In Situ Hybridization, Fluorescence/methods* ; Retrospective Studies ; Karyotyping ; Chromosome Aberrations ; Sex Chromosome Aberrations ; Karyotype ; Chromosome Banding ; Sex Chromosomes