1.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
2.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
3.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
4.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
5.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
6.Clinical value of fluorescence in situ hybridization with MDM2 and DDIT3 probe in diagnosis of liposarcoma.
Wei WANG ; Xin LI ; Ping LIU ; Ying DONG
Journal of Peking University(Health Sciences) 2023;55(2):228-233
OBJECTIVE:
To investigate the value of using MDM2 amplification probe and DDIT3 dual-color, break-apart rearrangement probe fluorescence in situ hybridization (FISH) technique in the diagnosis of liposarcoma.
METHODS:
In the study, 62 cases of liposarcoma diagnosed in Peking University First Hospital from January 2015 to December 2019 were analysed for clinicopathological information. Of these 62 cases of liposarcoma, all were analysed for MDM2 amplification and 48 cases were analysed for DDIT3 rearrangement using a FISH technique. Our study aimed to evaluate the status of MDM2 and DDIT3 by FISH in liposarcoma and correlate it with diagnosis of different subtypes of liposarcoma. The subtypes of liposarcoma were classified according to the FISH results, combined with the relevant clinicopathological features.
RESULTS:
The patients aged 31-89 years (mean: 59 years) with a 1.75:1 male to female ratio. Histologically, there were 20 cases of atypical lipomatous tumour/well-differentiated liposarcoma (ALT/WDLPS), 26 cases of dedifferentiated liposarcoma (DDLPS), 13 myxoid liposarcoma (MLPS) and 3 pleomorphic liposarcoma (PLPS). Tumors with DDLPS (23/26) and WDLPS (8/20) were localized retroperitoneally, while both tumours of MLPS and PLPS were localized extra-retroperitoneally, and the difference of sites among the four subtypes of liposarcoma was statistically significant (P < 0.05). Histologically, varied mucoid matrix could be observed in the four subtypes of liposarcoma, and the difference was statistically significant (P < 0.05). MDM2 gene amplification was demonstrated in all cases of ALT/WDLPS and DDLPS (100%, 20/20 and 26/26 respectively); DDIT3 gene rearrangement was noted only in MLPS (100%, 13/13); most cases of DDLPS (96.2%, 25/26) and ALT/WDLPS (83.3%, 5/6, 6 cases selected for detection) demonstrated the picture of amplification of the DDIT3 telomeric tag. According to the instructions of DDIT3 break-apart rearrangement probe, the 5' telomere probe and 3' centromere probe spanned but did not cover the DDIT3 gene itself, on the contrary, the 5' telomere probe covered the CDK4 gene, while the DDIT3 and CDK4 gene were located adjacent to each other on chromosome, therefore, when the amplification signal appeared on the telomeric tag of the DDIT3 rearrangement probe, it indeed indicated the CDK4 gene amplification rather than the DDIT3 gene rearrangement. Then the 10 cases with DDIT3 telomeric tag amplification were selected for CDK4 and DDIT3 gene amplification probe FISH tests, and all the cases showed CDK4 gene amplification (100%, 10/10) and two of the 10 cases demonstrated co-amplification of CDK4 and DDIT3 (20%, 2/10); DDIT3 polysomy detected by DDIT3 gene rearrangement probe was found in 1 case of DDLPS and 2 cases of PLPS (66.7%, 2/3) with morphology of high-grade malignant tumour and poor prognosis.
CONCLUSION
Our results indicate that a diagnosis of different subtype liposarcoma could be confirmed based on the application of MDM2 and DDIT3 FISH, combined with clinicopathological findings. It is also noteworthy that atypical signals should be correctly interpreted to guide correct treatment of liposarcomas.
Male
;
Female
;
Humans
;
In Situ Hybridization, Fluorescence/methods*
;
Cyclin-Dependent Kinase 4/metabolism*
;
Liposarcoma/pathology*
;
Lipoma/pathology*
;
Gene Amplification
;
Transcription Factor CHOP/genetics*
;
Proto-Oncogene Proteins c-mdm2/metabolism*
7.Clinicopathological features and prognosis of breast cancer with human epidermal growth factor receptor 2 low expression.
Xiao Juan ZHU ; Hong ZHANG ; Shuang ZHANG ; Dong LI ; Xin LI ; Ling XU ; Ting LI
Journal of Peking University(Health Sciences) 2023;55(2):243-253
OBJECTIVE:
There is an increasing interest in human epidermal growth factor receptor 2 (HER2) low expression breast cancer with the result of novel anti-HER2 antibody-drug conjugates for breast cancer. HER2 low expression breast cancer is expected to become a new type of breast cancer. This study analyzed and compared the clinicopathological features and survival data of breast cancer with HER2 low expression group [immunohistochemistry (IHC) 1+ or IHC 2+, and fluorescence in situ hybridization (FISH) negative] and HER2 zero expression group (IHC 0), in order to explore the difference in clinical biology of HER2 low expression breast cancers.
METHODS:
Among 1 250 female patients with primary non-metastatic breast cancer admitted to the Breast Disease Center of Peking University First Hospital from January 2014 to December 2017, 969 cases were HER2 negative (IHC 0, 1+, 2+, and FISH was not amplified). The clinicopathologic features and prognosis of the patients with HER2 low expression (IHC 1+ or 2+, and unamplified by FISH) and HER2 zero expression (IHC 0) were analyzed. Disease free survival (DFS) and overall survival (OS) were evaluated, survival rates were calculated by Kaplan-Meier curve, and survival differences were compared by Log-rank test. Cox regression analysis of univariate and multivariate prognostic factors. Bilateral test was used, and P < 0.05 was considered statistically significant.
RESULTS:
In the 969 patients with HER2 negative breast cancer, 606 had HER2 low expression (62.54%) and 363 had HER2 zero expression (37.46%). Compared with breast cancer with HER2 zero expression, those with HER2 low expression had higher N stage (P=0.001) and TNM stage (P=0.044), the proportion of non-specific histological types was higher (82.7% vs. 79.1%, P=0.009), the histological grade was higher (P=0.048), and the positive rate of hormone receptor was higher (83.2% vs. 75.2%, P=0.003). The percentage of Ki-67 value index >30% was lower (30.4% vs. 36.6%, P=0.044). There was no significant difference in DFS and OS between the two groups (P>0.05). In the 969 cases, 777 were hormone receptor positive and 192 were hormone receptor negative (triple negative cancer). Among the 777 cases with hormone receptor positive, 504 (64.9%) were HER2 low expression, and 273 (35.1%) were HER2 zero expression. Compared with breast cancer with HER2 zero expression group, the HER2 low expression group had a younger age (P=0.016), a higher proportion of premenopausal patients (P=0.029), more lymph node involvement (P=0.002), and a higher total TNM stage (P=0.031), and less frequent histological types of lobular and mucinous carcinoma (3.6% vs. 7.3%, 4.8% vs. 10.6%, P=0.001). There was no difference in DFS and OS between HER2 low expression and zero expression (P>0.05). Among 192 patients with hormone receptor negative, there were 102 cases (53.1%) with HER2 low expression and 90 cases (46.9%) with HER2 zero expression. Compared with the HER2 zero expression groups, HER2 low expression group was older (P=0.001), the proportion of premenopausal patients was low (P=0.029), the histological grade was lower (P < 0.001), the Ki-67 value index was lower (P < 0.001), and androgen receptor positive rate was higher (58.8% vs. 34.4%, P < 0.001). DFS was better than HER2 zero expression group (P=0.038), but there was no difference in OS between the two groups (P>0.05).
CONCLUSION
HER2 low expression breast cancer accounts for about half of all breast cancers, and the incidence is much higher than that of HER2 positive breast cancer. Its clinicopathologic features are heterogeneous, and the status of hormone receptor expression has an impact on the clinical biology of this group.
Humans
;
Female
;
Breast Neoplasms
;
Ki-67 Antigen
;
In Situ Hybridization, Fluorescence
;
Prognosis
;
Hormones
8.Mucinous tubular and spindle cell carcinoma of kidney: Clinicopathology and prognosis.
Qi SHEN ; Yi Xiao LIU ; Qun HE
Journal of Peking University(Health Sciences) 2023;55(2):276-282
OBJECTIVE:
To investigate and summarize the clinicopathological features, immunophenotype, differential diagnosis and prognosis analysis of mucinous tubular and spindle cell carcinoma (MTSCC).
METHODS:
The data of thirteen cases of MTSCC were retrospectively analyzed, the clinical and pathological characteristics and immunohistochemical expression were summarized, and fluorescence in situ hybridization was detected.
RESULTS:
Among the thirteen patients, four were males and nine females, with a male-to-female ratio of 1 ∶2.25. The average age was 57.1 years, ranging from 39 to 78 years. The maximum diameter of the tumor was 2-12 cm. All cases had no symptoms, and were accidentally discovered, 3 cases underwent partial renal resection, 10 cases underwent radical renal resection, 9 cases were located in the left kidney, and 4 cases were located in the right kidney. Most of the cases showed the classical morphological changes, with 11 cases of nuclear grading [World Health Organization (WHO)/International Society of Urological Pathology (ISUP) grading system] being G2 and 2 cases being G3. There were 6 cases of stage PT1a, 3 cases of PT1b, 2 cases of PT2a, and 1 case of PT2b and 1 case of PT3a. The positive rates of immunohistochemical staining were: vimentin, AE1/AE3, α-methylacyl-CoA racemase (αMACR) and cytokeratin (CK) 8/18, 100% (13/13); CK7, 92.3% (12/13); epithelial membrane antigen (EMA), 92.3% (12/13); CK20, 46.2% (6/13); CD10, 30.8% (4/13); synaptophysin (Syn), 7.7% (1/13); chromogranin A (CgA), CD57, WT1 and Ki-67, 0 (0/13), and fluorescence in situ hybridization showed that no trisomy of chromosomes 7 and 17 were observed in any of the cases. The follow-up period was 6 months to 7 years and 6 months, 2 cases died after lung metastasis (one with ISUP/WHO grade G3, one with necrosis), and the remaining 11 cases had no recurrence and metastasis.
CONCLUSION
MTSCC is a unique type of low-grade malignancy kidney tumor, occurs predominantly in females, widely distributed in age, the current treatment method is surgical resection, and cases with necrosis and high-grade morphology are prone to recurrence and metastasis, although most cases have a good prognosis, but they still need close follow-up after surgery.
Humans
;
Male
;
Female
;
Middle Aged
;
Kidney Neoplasms/surgery*
;
Carcinoma, Renal Cell/diagnosis*
;
In Situ Hybridization, Fluorescence
;
Retrospective Studies
;
Adenocarcinoma, Mucinous/pathology*
;
Kidney/pathology*
;
Prognosis
;
Necrosis
9.Genetic analysis of a Fra(16)(q22) fragile site in a female with secondary infertility.
Chengxiu XIE ; Chonglan GAO ; Han KANG ; Qingsong LIU
Chinese Journal of Medical Genetics 2023;40(4):495-499
OBJECTIVE:
To explore the genetic basis for a Fra(16)(q22)/FRA16B fragile site in a female with secondary infertility.
METHODS:
The 28-year-old patient was admitted to Chengdu Women's and Children's Central Hospital on October 5, 2021 due to secondary infertility. Peripheral blood sample was collected for G-banded karyotyping analysis, single nucleotide polymorphism array (SNP-array), quantitative fluorescent polymerase chain reaction (QF-PCR) and fluorescence in situ hybridization (FISH) assays.
RESULTS:
The patient was found to harbor 5 mosaic karyotypes involving chromosome 16 in a total of 126 cells, which yielded a karyotype of mos 46,XX,Fra(16)(q22)[42]/46,XX,del(16)(q22)[4]/47,XX,del(16),+chtb(16)(q22-qter)[4]/46,XX,tr(16)(q22)[2]/46,XX[71]. No obvious abnormality was found by SNP-array, QF-PCR and FISH analysis.
CONCLUSION
A female patient with FRA16B was identified by genetic testing. Above finding has enabled genetic counseling of this patient.
Female
;
Humans
;
In Situ Hybridization, Fluorescence
;
Chromosome Fragile Sites
;
Karyotyping
;
Karyotype
;
Infertility
10.The value of chromosomal microarray analysis and fluorescence in situ hybridization for the prenatal diagnosis of chromosomal mosaicisms.
Jianli ZHENG ; Ning AN ; Min LI ; Mengjun XU ; Yongjuan GUAN ; Jianbin LIU
Chinese Journal of Medical Genetics 2023;40(5):527-531
OBJECTIVE:
To assess the value of chromosomal microarray analysis (CMA) and fluorescence in situ hybridization (FISH) for the prenatal diagnosis of chromosomal mosaicisms.
METHODS:
A total of 775 pregnant women who had visited the Prenatal Diagnosis Center of Yancheng Maternal and Child Health Care Hospital from January 2018 to December 2020 were selected as study subjects. Chromosome karyotyping analysis and CMA were carried out for all women, and FISH was used to validate the suspected mosaicism cases.
RESULTS:
Among the 775 amniotic fluid samples, karyotyping has identified 13 mosaicism cases, which yielded a detection rate of 1.55%. Respectively, there were 4, 3, 4 and 2 cases for sex chromosome number mosaicisms, abnormal sex chromosome structure mosaicisms, abnormal autosomal number mosaicisms and abnormal autosomal structure mosaicisms. CMA has only detected only 6 of the 13 cases. Among 3 cases verified by FISH, 2 cases were consistent with the karyotyping and CMA results, and clearly showed low proportion mosaicism, and 1 case was consistent with the result of karyotyping but with a normal result by CMA. Eight pregnant women had chosen to terminate the pregnancy (5 with sex chromosome mosaicisms and 3 with autosomal mosaicisms).
CONCLUSION
For fetuses suspected for chromosomal mosaicisms, CMA, FISH and G-banding karyotyping should be combined to determine the type and proportion of mosaicisms more precisely in order to provide more information for genetic counseling.
Female
;
Pregnancy
;
Humans
;
Mosaicism
;
In Situ Hybridization, Fluorescence
;
Chromosome Disorders/genetics*
;
Prenatal Diagnosis/methods*
;
Chromosome Aberrations
;
Sex Chromosome Aberrations
;
Microarray Analysis/methods*
;
Chromosomes

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