1.Molecular cytogenetic analysis and diagnosis of three fetuses with psu idic(Y)(q11.22) using a combination of multiple techniques.
Xuejiao CHEN ; Meizhen DAI ; Milei ZHU ; Weiwu SHI
Chinese Journal of Medical Genetics 2025;42(3):360-367
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
2.Application value of chromosomal microarray analysis for the detection of low-level mosaicisms in amniotic fluid samples and analysis of rare cases.
Huiyuan SHAO ; Zongyu MIAO ; Hong WU ; Lei LI ; Xiaoyan LIU ; Yuping WANG ; Lihua JIANG
Chinese Journal of Medical Genetics 2025;42(4):441-445
OBJECTIVE:
To assess the value of chromosomal microarray analysis (CMA) for the detection of low-level mosaicisms in amniotic fluid samples, and to retrospectively analyze the rare cases of mosaicisms.
METHODS:
Chromosomal karyotype of the fetus was determined by G-banding analysis of cultured amniotic fluid cells. CMA was used to detect copy number variation of fetal chromosomes, and fluorescence in situ hybridization (FISH) was used to determine the proportion of fetal chromosomal mosaicisms in uncultured amniotic fluid cells.
RESULTS:
Among 825 prenatal samples, 4 cases of true fetal mosaicisms were detected, which yielded an incidence of 0.48%. Two cases were sex chromosomal mosaicisms, and two were autosomal mosaicisms, which involved chromosomes 8 and 9, respectively. All cases were verified by G-banding analysis of cultured amniotic fluid cells, CMA, and/or FISH.
CONCLUSION
CMA has a great value for detecting low-level mosaicisms in amniotic fluid samples, though the positive results need to be verified by other techniques and should be interpreted with caution. The review of rare cases can provide a basis for prenatal genetic counseling.
Humans
;
Female
;
Amniotic Fluid/metabolism*
;
Pregnancy
;
Mosaicism/embryology*
;
Prenatal Diagnosis/methods*
;
Adult
;
In Situ Hybridization, Fluorescence
;
Microarray Analysis/methods*
;
Karyotyping
;
Retrospective Studies
;
Male
3.Clinical characteristics and genetic analysis of four patients with Disorders of sex development.
Xiuyan WANG ; Fanrong MENG ; Yunfang SHI ; Duan JU ; Xinghong ZHOU ; Haiwei DONG ; Xiaozhou LI
Chinese Journal of Medical Genetics 2025;42(9):1089-1095
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
4.Analysis of false-negative cases by Optical genome mapping and a literature review.
Junrong ZHANG ; Min SU ; Yuquan ZHANG ; Jianlin ZHANG
Chinese Journal of Medical Genetics 2025;42(11):1288-1294
OBJECTIVE:
To explore the reasons for false negative results by Optical genome mapping (OGM) analysis of three cases and propose strategies for handling them.
METHODS:
Three patients presented at the Affiliated Hospital of Nantong University between July 2022 and July 2024 were selected as study subjects. The patients included a 37-year-old female with two miscarriages, a 1.5-year-old boy with delayed motor development, and a 35-year-old male whose son had intellectual disability. The patients had undergone comprehensive evaluation with chromosomal karyotyping analysis, single nucleotide polymorphism microarray (SNP array) assay, fluorescence in situ hybridization (FISH), and methylation-specific multiple ligation-dependent probe amplification (MS-MLPA). A retrospective analysis was also carried out on the results of OGM testing. This study was approved by the Medical Ethics Committee of the Hospital (Ethics No.: 2020-K004).
RESULTS:
The chromosomal karyotype of patient 1 was 46,XX,4qs, and no abnormality was found by SNP array, FISH, and OGM testing. Patient 2 had a normal chromosomal karyotype, and SNP array analysis did not reveal any copy number abnormalities of chromosomal fragments but the presence of a homozygous region of approximately 79.58 Mb at 15q11.2-q26.3 (chr15: 22817871_102397317). MS-MLPA detection indicated that the copy number of the 15q11.2-q13 region was 2, and the degree of methylation was relatively high (average ratio = 1.0). OGM detection confirmed the presence of approximately 67.97 Mb of homozygosity in the chr15:33814680_101787650 [hg38] region of 15q14-q26.3. Patient 3 had a chromosomal karyotype of 46,XY,t(9;14)(q13;q11.2). No abnormality was found by OGM testing for patients 1 and 3.
CONCLUSION
As a novel cytogenetic technique, OGM can achieve high-resolution and high-precision analysis for numerical and structural genomic abnormalities. Nevertheless, it also has certain limitations, as its false negative results are related to factors such as the type of genomic variation, the chromosomal regions involved in the variation, the type of disease, and the version of human reference genome. Currently, it cannot be used as an independent method for the diagnosis of genetic diseases.
Humans
;
Male
;
Female
;
Adult
;
Polymorphism, Single Nucleotide/genetics*
;
Karyotyping
;
Chromosome Mapping/methods*
;
Infant
;
False Negative Reactions
;
In Situ Hybridization, Fluorescence
5.Genetic analysis of a phenotypically normal male with SRY gene-positive 46,XX/46,XY tetrameric chimerism.
Weiguo ZHANG ; Mengxue WU ; Zhi YANG ; Feiyan PAN ; Zhizhi HE ; Yiyang ZHU
Chinese Journal of Medical Genetics 2025;42(12):1502-1507
OBJECTIVE:
To investigate the clinical characteristics and genetic etiology of a male with a normal phenotype and SRY gene-positive 46,XX/46,XY tetrazoospermia chimerism.
METHODS:
A male patient with an abnormal peripheral blood chromosomal karyotype detected at the Infertility Center of Taizhou Hospital of Zhejiang Province on December 2, 2013 was selected as the study subject. Peripheral venous blood samples were collected from the proband and his family members, together with a semen sample from the proband. Chromosomal karyotype analysis, red blood cell blood group identification, chromosomal microarray analysis (CMA), fluorescence in situ hybridization (FISH), sex-determining region Y (SRY) gene detection, and short tandem repeat (STR) microsatellite marker analysis were performed on the peripheral venous blood sample from the proband. Routine semen analysis, sperm FISH, and STR testing were also conducted. STR verification was performed on both parents. This study was approved by the Medical Ethics Committee of the hospital (Ethics No.: k20201009).
RESULTS:
The proband, a 37-year-old male, had normal secondary sexual characteristics and external genitalia development. The chromosomal karyotype of his peripheral blood sample was 46,XX[94]/46,XY[6]. ABO blood group typing was positive for Rh(D) type O and negative for Rh(D) type A, indicating the presence of two red blood cell populations. CMA result was arr[GRCh37](1-22)×2,(XX)×1. Autosomal and X chromosome SNP genotypes were BB-BB, AB-AB, and AA-AA, making it impossible to identify homozygous/heterozygous chimerism. FISH detection of interphase nuclei showed nuc ish XX[92]/XY[8]. Testing of the SRY gene was positive. STR analysis showed a single X peak (no Y peak) at the AMEL locus, 10/12 at the Penta D locus, and no third allele at other loci. Routine semen analysis were normal. Sperm FISH detection showed haploid nuclei nuc ish X[53]/Y[47]. Sperm STR analysis revealed an X/Y bimodal distribution at the AMEL locus and a 9/14 distribution at the Penta D locus, with no third allele observed at other loci. Above results suggested that the proband's blood and germ cell lines had originated from a heterozygous chimera formed by the fusion of two different zygotes.
CONCLUSION
Combined genetic techniques confirmed that the proband's peripheral blood AMEL genotype is X/X, while the sperm is X/Y. The Penta D locus showed a bi-allelic heterozygous pattern of 10/12 in the peripheral blood sample and 9/14 in the sperm sample, suggesting that the proband is a tetrazygotic chimera resulted from the fusion of 46,XX/46,XY zygotes.
Humans
;
Male
;
Adult
;
Chimerism
;
Microsatellite Repeats
;
Sex-Determining Region Y Protein/genetics*
;
Phenotype
;
Genes, sry
;
In Situ Hybridization, Fluorescence
;
Karyotyping
6.Cryptic COL1A1-PDGFB fusion in dermatofibrosarcoma protuberans: a clinicopathological and genetic analysis.
Min CHEN ; Yu Mei CHEN ; Yang LU ; Xin HE ; Heng PENG ; Hong Ying ZHANG
Chinese Journal of Pathology 2023;52(1):13-18
Objective: To investigate the clinicopathological and cytogenetic features of cryptic COL1A1-PDGFB fusion dermatofibrosarcoma protuberans (CC-DFSP). Methods: Three cases of CC-DFSP diagnosed in West China Hospital, Sichuan University, Chengdu, China from January 2021 to September 2021 were studied. Immunohistochemistry for CD34 and other markers, fluorescence in situ hybridization (FISH) for PDGFB, COL1A1-PDGFB and COL1A1, next-generation sequencing (NGS), reverse-transcriptase polymerase chain reaction (RT-PCR) and Sanger sequencing were performed. Results: There were three cases of CC-DFSP, including two females and one male. The patients were 29, 44 and 32 years old, respectively. The sites were abdominal wall, caruncle and scapula. Microscopically, they were poorly circumscribed. The spindle cells of the tumors infiltrated into the whole dermis or subcutaneous tissues, typically arranging in a storiform pattern. Immunohistochemically, the neoplastic cells exhibited diffuse CD34 expression, but were negative for S-100, SMA, and Myogenin. Loss of H3K27me3 was not observed in the tumor cells. The Ki-67 index was 10%-15%. The 3 cases were all negative for PDGFB rearrangement and COL1A1-PDGFB fusion, whereas showing unbalanced rearrangement for COL1A1. Case 1 showed a COL1A1 (exon 31)-PDGFB (exon 2) fusion using NGS, which was further validated through RT-PCR and Sanger sequencing. All patients underwent extended surgical resection. Except for case 3 with recurrence 2 years after surgical resection, the other 2 cases showed no recurrence or metastasis during the follow-up. Conclusions: FISH has shown its validity for detecting PDGFB rearrangement and COL1A1-PDGFB fusion and widely applied in clinical detection. However, for cases with negative routine FISH screening that were highly suspicious for DFSPs, supplementary NGS or at least COL1A1 break-apart FISH screening could be helpful to identify cryptic COL1A1-PDGFB fusions or other variant fusions.
Female
;
Humans
;
Male
;
Collagen Type I, alpha 1 Chain
;
Dermatofibrosarcoma/pathology*
;
In Situ Hybridization, Fluorescence
;
Oncogene Proteins, Fusion/genetics*
;
Proto-Oncogene Proteins c-sis/genetics*
;
Skin Neoplasms/pathology*
;
Adult
7.EWSR1-SMAD3 positive fibroblastic tumor: a clinicopathological analysis.
Hai Yan SU ; Lu ZHAO ; Gang JI ; Qian Lan YAO ; Qian Ming BAI ; Xiao Yan ZHOU ; Jian WANG
Chinese Journal of Pathology 2023;52(1):19-24
Objective: To investigate the clinicopathological features, immunophenotypes and molecular genetics of EWSR1-SMAD3 positive fibroblastic tumor (ESFT) with an emphasis on differential diagnosis. Methods: The clinicopathological data, immunohistochemical profiles and molecular profiles of 3 ESFT cases diagnosed at the Department of Pathology, Fudan University Shanghai Cancer Center from 2018 to 2021were analyzed. The related literature was also reviewed. Results: There were two males and one female. The patients were 24, 12 and 36 years old, respectively. All three tumors occurred in the subcutis of the foot with the disease duration of 6 months to 2 years. The tumors were presented with a slowly growing mass or nodule, accompanied with pain in 1 patient. The tumors ranged in size from 0.1 to 1.6 cm (mean, 1.0 cm). Microscopically, the tumors were located in the subcutaneous tissue with a nodular or plexiform growth pattern. They were composed of cellular fascicles of bland spindle cells with elongated nuclei and fine chromatin. One of the tumors infiltrated into adjacent adipose tissue. There was no nuclear atypia or mitotic activities. All three tumors showed prominent stromal hyalinization with zonal pattern present in one case. Focal punctate calcification was noted in two cases. The immunohistochemical studies showed that tumor cells were diffusely positive for ERG and negative for CD31 and CD34, with Ki-67 index less than 2%. Fluorescence in situ hybridization on the two tested cases identified EWSR1 gene rearrangement. The next generation sequencing analysis demonstrated EWSR1-SMAD3 fusion in all three cases. During the follow up, one patient developed local recurrence 24 months after the surgery. Conclusions: ESFT is a benign fibroblastic neoplasm and has a predilection for the foot, characterized by ERG immunoreactivity and EWSR1-SMAD3 fusion. Local recurrence might occur when incompletely excised. Familiarity with its clinicopathological features is helpful in distinguishing it from other spindle cell neoplasms that tend to occur at acral sites.
Adult
;
Child
;
Female
;
Humans
;
Male
;
Biomarkers, Tumor/analysis*
;
China
;
In Situ Hybridization, Fluorescence
;
Neoplasms, Fibrous Tissue/pathology*
;
RNA-Binding Protein EWS/genetics*
;
Smad3 Protein/genetics*
;
Soft Tissue Neoplasms/surgery*
8.Comparison of detection rates of chromosome G-banding karyotype analysis and fluorescence in situ hybridization among children with sex chromosome mosaicisms.
Weiwei XIAO ; Juan HUANG ; Wei LIU ; Bing LI ; Zhe SU ; Lili PAN ; Yunsheng CHEN
Chinese Journal of Medical Genetics 2023;40(1):12-16
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
9.Prenatal diagnosis for a fetus with 5p deletion syndrome.
Jun WANG ; Weiguo ZHANG ; Huanli YANG ; Xuejuan MA ; Jiexian LI ; Xing CHEN
Chinese Journal of Medical Genetics 2023;40(1):101-104
OBJECTIVE:
To explore the genetic basis for a fetus with club foot detected upon mid-pregnancy ultrasonography.
METHODS:
Amniotic fluid of the fetus and peripheral blood samples of its parents were collected and subjected to G-banding karyotype analysis and copy number variation sequencing (CNV-seq). The result was verified by fluorescence in situ hybridization (FISH).
RESULTS:
The fetus and its parents all had a normal karyotype. CNV-seq analysis revealed that the fetus has harbored a 23.12 Mb on chromosome 5 and a 21.46 Mb duplication on chromosome 7. FISH assay has verified that its mother has carried a cryptic t(5;7)(p14.3;q33) translocation.
CONCLUSION
CNV-seq combined with FISH can effectively detect cryptic chromosome aberrations, and can help to reduce severe birth defects and provide a basis for prenatal genetic counseling.
Pregnancy
;
Female
;
Humans
;
Cri-du-Chat Syndrome
;
In Situ Hybridization, Fluorescence
;
DNA Copy Number Variations
;
Prenatal Diagnosis
;
Fetus
;
Amniotic Fluid
;
Chromosome Deletion
10.Genetic features of a case with mosaic ring chromosome 4 and a review of the literature.
Canling MA ; Yingying WANG ; Na ZHEN ; Changxi SHAO ; Daoling ZHANG ; Yan JIANG ; Yu DU ; Yifang JIA
Chinese Journal of Medical Genetics 2023;40(1):105-109
OBJECTIVE:
To explore the genetic basis, clinical phenotype and pathogenesis for a child with mosaicism ring chromosome 4.
METHODS:
Clinical data of the child was collected. Peripheral blood chromosomal karyotype G banding analysis, chromosomal microarray analysis (CMA), fluorescence in situ hybridization (FISH) were carried out for the child, in addition with a review of the literature.
RESULTS:
The child was born full-term with low birth weight, facial dysmorphism, patent ductus arteriosus and ventricular septal defect. His karyotype was determined as mos46,XY,r(4)(p16.3q35.2)[259]/45,XY,-4[25]/47,XY,r(4)(p16.3q35.2), +r(4)(p16.3q35.2)[8]/46,XY,der(4)del(4)(p16.3)inv(4)(p16.3q31.1)[6]/46,XY,dic?r(4;4)(p16.3q35.2;p16.3q35.2)[4]/48,XY,r(4)(p16.3q35.2),+r(4)(p16.3q35.2)×2[3]/46,XY,r(4)(p1?q2?)[2]; CMA result was arr[GRCH37]4p16.3(68 345-2 981 614)×1; FISH result was 45,XY,-4[12]/45,XY,-4×2,+mar1.ish r1(4)(WHS-,D4Z1+)[1]/ 46,XY,-4,+mar1.ishr1(4)(WHS-,D4Z1+)[73]/46,XY,-4,+mar2.ishr2(4)(WHS-,D4Z1++)[1]/47,XY,-4,+mar1×2.ishr1(4) (WHS-, D4Z1+)×2[4]/46,XY,del(4)(p16.3).ish del(4)(p16.3)(WHS-,D4Z1+)[9].
CONCLUSION
In this case, the ring chromosome 4 as a de novo variant has produced a number of cell lines during embryonic development and given rise to mosaicism. The clinical phenotype of ring chromosome 4 is variable. The instability of the ring chromosome itself, presence of mosaicism, chromosome breakpoint and range of deletion and/or duplication may all affect the ultimate phenotype.
Humans
;
Pregnancy
;
Female
;
Ring Chromosomes
;
In Situ Hybridization, Fluorescence
;
Karyotyping
;
Karyotype
;
Mosaicism

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