1.Prenatal diagnosis of 22q11.2 microduplication syndrome in a three-generation family: Clinical-genetic characteristics and literature review.
Yifan LIAO ; Yidong WEN ; Xiaoqin DENG ; Cimo WANG ; Zhirong SHANG ; Jinghong YANG ; Jiabing LI
Chinese Journal of Medical Genetics 2026;43(1):57-63
OBJECTIVE:
To explore the genetic etiology for a pregnant woman with a history of multiple adverse pregnancies and assess the phenotype-genotype correlation of 22q11.2 microduplication syndrome in her family.
METHODS:
Amniotic fluid sample was taken from a pregnant woman for whom non-invasive prenatal screening indicated chromosome 22 abnormalities in the fetus. Peripheral blood samples from the woman, her brother and parents were collected for high-throughput low-depth whole genome sequencing (CNV-seq). A pedigree traceability analysis of the results was conducted in conjunction with analysis of clinical manifestation. Relevant literature (from establishment to March 2025) was systematically searched. This study was approved by the Medical Ethics Committee of Mianyang Maternal and Child Health Care Hospital (Ethics No.: Lun Shen [2024]009).
RESULTS:
CNV-seq revealed that the fetus had harbored a 6.02 Mb duplication at 22q11.21q11.23. Karyotyping confirmed it as 46,X?dup(22)(q11.2). Pedigree verification demonstrated that the pregnant woman, her brother and mother had all carried the same duplication. Phenotypic analysis of the affected family members showed classic features of 22q11.2 microduplication syndrome, including hypernasal speech, low nasal bridge, congenital heart disease, and cognitive impairment. A total of 44 cases with full information (including three patients from this pedigree) were included in the analysis. The penetrance of 22q11.2 duplication was approximately 29.5% (13/44), and 52.3% (23/44) of the cases had inherited the variant from a phenotypically normal parent.
CONCLUSION
This study has identified the genetic basis for the woman's recurrent adverse pregnancies and phenotypic abnormalities in her family members. The scoliosis identified in her younger brother has not been previously reported, thereby may enrich the clinical phenotype of this syndrome. For fetuses identified with a 22q11.2 microduplication, detailed fetal imaging is recommended, and genetic counseling should be provided to the couples.
Humans
;
Female
;
Pregnancy
;
Prenatal Diagnosis/methods*
;
Chromosome Duplication/genetics*
;
Male
;
Pedigree
;
DiGeorge Syndrome/diagnosis*
;
Adult
;
Chromosomes, Human, Pair 22/genetics*
;
Abnormalities, Multiple
2.Genetic analysis of two cases of submicroscopic chromosomal structural variants leading to abnormal pregnancies.
Chengxiu XIE ; Xiong ZHU ; Yacong WANG ; Qingsong LIU
Chinese Journal of Medical Genetics 2026;43(2):143-150
OBJECTIVE:
To investigate the genetic mechanism for adverse pregnancies due to submicroscopic chromosomal structural variants in two cases, and to provide a precise guidance for preimplantation genetic testing.
METHODS:
Two families who had visited Chengdu Women's and Children's Central Hospital for reproduction guidance due to recurrent miscarriages, adverse pregnancy history and abnormal genetic testing of the offspring in June and December 2023 were selected as the study subjects. Chromosomal karyotyping and optical genome mapping (OGM) were carried out on peripheral blood samples from the two couples, and preimplantation genetic testing for structural rearrangement (PGT-SR) were performed on the blastocyst trophoblasts. This study was approved by the Medical Ethics Committee of the Hospital (Ethic No.: 2023-23).
RESULTS:
No abnormality was found on the G-banded karyotyping analysis for both couples. The OGM results revealed that the female partner of couple 1 had a translocation between 4pter-p16.3 (3.99 Mb) and 11pter-p15.4 (2.66 Mb), whilst no abnormality was found in the male partner. Similarly, the male partner of couple 2 had a translocation between 19q13.43-qter (1.90 Mb) and 22q13.31-qter (3.34 Mb). No abnormality was found in the female partner of couple 2. Neither breakpoints nor the adjacent region had involved an OMIM gene, except the formation of a fusion gene ZIM2-AS1-Z82186.1 (Both genes are non-coding, and the fusion gene was deemed as variant of unknown significance). PGT-SR of 11 blastocysts derived from couple 1 revealed that one embryo was suitable for priority transfer, three embryos were suitable for transfer, one embryo was recommended for genetic counselling, and six embryos were unsuitable for the transfer. For couple 2, six blastocysts were tested, of which only one embryo was deemed suitable for transfer.
CONCLUSION
When genetic testing of offspring indicates copy number variations such as deletions, duplications or mosaicism, the high-resolution OGM technique can be selected to screen parents for submicroscopic chromosomal structural variations. The result can facilitate accurate assessment for the risk of recurrence in offspring, selection of suitable method for reproduction, and identifying targets for PGT.
Humans
;
Female
;
Pregnancy
;
Adult
;
Male
;
Karyotyping
;
Chromosome Aberrations
;
Abortion, Habitual/genetics*
;
Preimplantation Diagnosis
;
Genetic Testing
3.Application of artificial intelligence-assisted chromosome karyotyping analysis in prenatal diagnosis of chromosomal mosaicism.
Ling ZHAO ; Shiwei SUN ; Qinghua ZHENG ; Qing YU ; Chongyang ZHU ; Ling LIU ; Yueli WU
Chinese Journal of Medical Genetics 2026;43(3):180-187
OBJECTIVE:
To explore the application value of artificial intelligence (AI)-assisted chromosomal karyotype analysis in the diagnosis of prenatal chromosomal mosaicism.
METHODS:
A retrospective analysis was conducted on 172 pregnant women who underwent amniocentesis at the Department of Medical Genetics and Prenatal Diagnosis, the Third Affiliated Hospital of Zhengzhou University between January 2019 and December 2024. All cases whose fetuses were diagnosed with chromosomal mosaicism via karyotype analysis and stratified into two groups based on the analytical software employed: the conventional analysis group (n = 70), which utilized Leica analysis software for karyotype image recognition and cell counting; and the AI-assisted analysis group (n = 102), which utilized AI-assisted software for the same procedures. The clinical performance of AI-assisted karyotype analysis in diagnosing chromosomal mosaicism was comprehensively evaluated by comparing the types of mosaic karyotypes, distribution of mosaic ratios, and verification outcomes of different detection modalities between the two groups. This study was approved by the Medical Ethics Committee of the Third Affiliated Hospital of Zhengzhou University (Ethics No.: 2024-406-01).
RESULTS:
No statistically significant difference was observed in baseline characteristics (maternal age, gestational week, and indications for prenatal diagnosis) between the two groups. Regarding the detection efficacy for numerical and structural mosaicisms, no significant difference was found in the detection of numerical mosaicism. However, the conventional analysis group exhibited a significantly higher detection rate of autosomal structural mosaicism compared to the AI-assisted group (11.43% vs. 0.98%, P < 0.05). Numerical mosaicism cases were further verified using copy number variation sequencing (CNV-seq) and/or fluorescence in situ hybridization (FISH). The AI-assisted group demonstrated a significantly lower inconsistency rate (5.56% vs. 20.41%, P < 0.05) compared to the conventional group. For low-proportion (< 10%) chromosomal mosaicism, the AI-assisted group had a significantly lower detection rate (13.25% vs. 29.69%, P < 0.05). Subsequent validation of low-proportion mosaicism by CNV-seq and/or FISH showed a higher consistency rate in the AI-assisted group (81.82% vs. 54.55%), though the difference did not reach statistical significance (P = 0.360).
CONCLUSION
For the karyotyping analysis of prenatal chromosomal mosaicism, AI-assisted karyotype analysis shows high accuracy and consistency in identifying numerical chromosomal mosaicism, particularly in reducing the detection of low-proportion (< 10%) mosaicism while improving verification accuracy. AI-assisted analysis can significantly improve the detection accuracy of numerical mosaicism and mitigate the risk of misclassification for low-proportion (< 10%) mosaicism, thereby providing more precise clinical evidence for the prenatal diagnosis of chromosomal mosaicisms.
Humans
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Female
;
Mosaicism
;
Pregnancy
;
Karyotyping/methods*
;
Artificial Intelligence
;
Prenatal Diagnosis/methods*
;
Adult
;
Retrospective Studies
;
Chromosome Disorders/genetics*
;
Amniocentesis
4.Prenatal diagnosis and genetic counseling of 20 fetuses with 15q11.2 BP1-BP2 microdeletion syndrome.
Meijuan LI ; Xinyou YU ; Lanhua YANG ; Xiaoyan WANG ; Bo WEI
Chinese Journal of Medical Genetics 2025;42(1):64-68
OBJECTIVE:
To explore the clinical phenotype, pregnancy outcome and follow-up of fetuses with 15q11.2BP1-BP2 microdeletions in order to provide a basis for prenatal and reproductive consultation.
METHODS:
From March 2019 to December 2023, 20 fetuses who were diagnosed with 15q11.2BP1-BP2 microdeletion syndrome at the Prenatal Diagnosis Center of General Hospital of Ningxia Medical University were selected as the study subjects. Results of genetic testing and ultrasound examination, outcome of pregnancy, and postnatal follow-up were retrospectively analyzed. This study has been approved by the Ethics Committee of General Hospital of Ningxia Medical University ([2020]0520B).
RESULTS:
None of the 20 fetuses was found to have chromosomal abnormality, whilst all were found to harbor a 15q11.2 BP1-BP2 microdeletion by low-depth whole genome sequencing (CNV-seq). The range of deletions was determined as 0.26 ~ 0.87 Mb, and all were rated as pathogenic CNVs. Three fetuses had abnormal ultrasound findings, including 1 with widened renal pelvis, 1 with agenesis of corpus callosum, and 1 with nuchal fold thickening. Parental verification in 10 couples verified that two fetal deletions were de novo, whilst the remaining eight were inherited from a phenotypically normal parent. Following genetic counseling, three couples had opted to terminate the pregnancy, whilst the remaining 17 had continued with the pregnancy until delivery. The 17 liveborns were followed up for 2 months to 5 years, with no obvious abnormality in growth and development noted.
CONCLUSION
CNV-seq plays an important role in the prenatal diagnosis of 15q11.2 BP1-BP2 microdeletions. Such deletions may not always lead to disease phenotypes. Individualized consultation and long-term follow-up, in combination with intrauterine ultrasound and parental verification are necessary.
Humans
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Female
;
Pregnancy
;
Chromosomes, Human, Pair 15/genetics*
;
Genetic Counseling
;
Prenatal Diagnosis
;
Chromosome Deletion
;
Adult
;
Fetus/abnormalities*
;
Retrospective Studies
;
Pregnancy Outcome
;
Ultrasonography, Prenatal
;
Genetic Testing
;
DiGeorge Syndrome/diagnosis*
;
Male
5.Genetic analysis of a Chinese pedigree with rare mosaic 11q partial duplication and a literature review.
Lili ZHOU ; Chenyang XU ; Hao WU ; Sheng HUANG ; Xueqin XU ; Xiaohua TANG
Chinese Journal of Medical Genetics 2025;42(1):94-101
OBJECTIVE:
To explore the genetic characteristics of a Chinese pedigree with rare mosaic 11q partial duplication and its pathogenetic mechanisms.
METHODS:
A pedigree which underwent prenatal diagnosis at Wenzhou Central Hospital between September 25, 2015 and November 30, 2023 was selected for the study. Clinical data were collected from the pedigree. Peripheral blood samples from the parents, amniotic fluid from the fetus, and peripheral blood sample from the neonate were obtained. Genetic testing was carried out by using G-banded chromosomal karyotyping and single nucleotide polymorphism array (SNP-array) technology. Relevant literature was searched in the CNKI, Wanfang Data Knowledge Service Platform, and PubMed databases to summarize the clinical phenotypes of patients with 11q partial duplication. This study was approved by the Medical Ethics Committee of Wenzhou Central Hospital (Ethics No. L2024-07-080).
RESULTS:
The pregnant woman (G3) had a history of adverse pregnancy outcomes. During her first pregnancy (G1), prenatal ultrasound indicated intrauterine growth restriction and a Dandy-Walker variant. Follow-up at 8 years of age showed developmental delays and mild intellectual disability. During her second pregnancy (G2), prenatal ultrasound revealed nasal bone hypoplasia, and the pregnancy was terminated at 23rd gestational week. During her third pregnancy (G3), all prenatal tests were normal, and the neonate showed normal growth and development at 4 months of age. The karyotype of amniotic fluid of her first pregnancy was 46,X?, and the SNP-array analysis of neonatal peripheral blood showed arr[GRCh37/hg19]11q13.4q25(70432450_134607121)×2~3, with a mosaicism rate being approximately 40%. The karyotype for her second pregnancy was 46,X?,rec(11)dup(11q)inv(11)(p15q13)dmat[6]/46,X?[27], and the SNP-array result was arr[GRCh38]11q13.4q25(71406636_135067522)×2~3, with a mosaicism rate being approximately 75%. The karyotype for her third pregnancy was 46,X?,inv(11)(p15q13)mat, and the SNP-array result was arr(XN)×1,(1~22)×2. The karyotype of the woman was 46,XX,inv(11)(p15q13), and that of her husband was 46,XY. A review of 12 similar cases (including G1) from the literature revealed that the common clinical phenotypes of 11q partial duplication included intellectual disability (12/12), developmental delay (12/12), ear abnormalities (12/12), microcephaly (10/12), seizures (8/12), hypotonia (8/12), and congenital heart malformations (7/12).
CONCLUSION
Mosaic partial duplication of 11q may underlie the genetic etiology of this pedigree. The pregnant woman is a carrier of an inversion on chromosome 11, which might have formed the mosaic 11q partial duplication through meiotic errors and mitotic trisomy rescue mechanisms during reproduction.
Adult
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Female
;
Humans
;
Male
;
Pregnancy
;
China
;
Chromosome Duplication
;
Chromosomes, Human, Pair 11/genetics*
;
East Asian People/genetics*
;
Karyotyping
;
Mosaicism
;
Pedigree
;
Polymorphism, Single Nucleotide
;
Prenatal Diagnosis
6.Association between maternal age and chromosomal status of pre-implantation embryos.
Chunyan WEI ; Rong LI ; Changlong XU ; Ni'na LI ; Ying HUANG ; Jian ZHANG ; Qiuwen SHI
Chinese Journal of Medical Genetics 2025;42(3):257-263
OBJECTIVE:
To analyze the chromosome status of pre-implantation embryos from women of different ages, and assess the impact of age on it.
METHODS:
A retrospective analysis was carried out on the results of PGT-A and PGT-M+PGT-A cycles by whole-genome amplification followed by next generation sequencing at the Second People's Hospital of Nanning between July 2021 and November 2023. The embryos were divided into five groups based on the women's age: ≤ 30 years old group, 31 ~ 34 years old group, 35 ~ 37 years old group, 38 ~ 40 years old group, and ≥ 41 years old group.The chromosomal status of embryos for each group was compared. This study has been approved by the Ethic Committee of the Hospital (Ethics No. Y2024312A).
RESULTS:
This study has involved 390 couples and 436 PGT cycles, with a total of 1 651 blastocysts biopsied and analyzed. Among these, 835 embryos (50.6%) were found to have chromosomal abnormalities, including 490 (29.7%) with aneuploidies, 154 (9.3%) with chromosomal segment abnormalities, and 264 (16.0%) with chromosome mosaicisms. After adjusting the dosages of Gn, female BMI, male age, PGT indications, infertility type, LH, AMH and other parameters, maternal age appeared to be an independent factor for chromosomal abnormalities and aneuploidies in blastocysts (OR = 1.132, 95%CI = 1.089-1.177, P < 0.001; OR = 1.250, 95%CI = 1.188-1.315, P < 0.001). With the increase in female age, embryonic chromosome abnormalities have significantly increased in each group, with the rates being 32.3% (126/390), 43.1% (189/439), 45.1% (116/257), 66.3% (250/377), and 81.9% (154/188) (P < 0.001). Chromosomal aneuploidies have also significantly increased, with the rates being 8.2% (32/390), 16.6% (73/439), 24.5% (63/257), 49.6% (187/377), and 71.8% (135/188) (P < 0.001). The proportion of embryos with ≥ 2 chromosome abnormalities also significantly increased in abnormal embryos, with the rates being 28.6% (36/126), 30.2% (57/189), 39.7% (46/116), 48.4% (121/250), and 64.9% (100/154) (P < 0.001). Of note, the female age did not affect the prevalence of chromosomal segment abnormalities and mosaicisms (all P > 0.05).
CONCLUSION
Above findings suggested that along with the increase in female age, there is an increase in the rate and complexity of chromosomal abnormalities, which may contribute to infertility in women with elder age.
Humans
;
Female
;
Maternal Age
;
Adult
;
Retrospective Studies
;
Chromosome Aberrations
;
Preimplantation Diagnosis/methods*
;
Pregnancy
;
Blastocyst/metabolism*
;
Aneuploidy
;
Fertilization in Vitro
;
Male
7.Genetic analysis of two fetuses with Mosaic variegated aneuploidy syndrome caused by compound heterozygous variants in BUB1B and its upstream regulatory elements and a literature Review.
Jiangbo QU ; Wenjuan ZHU ; Ju WANG ; Lu GAO ; Dongyi YU
Chinese Journal of Medical Genetics 2025;42(4):446-453
OBJECTIVE:
To explore the genetic etiology of two fetuses with Mosaic variegated aneuploidy syndrome (MVA) in a pedigree.
METHODS:
A 30-year-old pregnant woman, who presented at the Center for Medical Genetics and Prenatal Diagnosis of Shandong Maternal and Child Health Care Hospital on November 16, 2023, was enrolled. Clinical data of the pedigree were collected, and peripheral blood samples from the parents and amniotic fluid samples from the two fetuses were obtained for genomic DNA extraction. Whole exome sequencing (WES) was performed on both fetuses, followed by Sanger sequencing for familial validation and pathogenicity analysis of candidate variants. Chromosomal karyotyping of the parents was conducted to quantify the proportion of premature chromatid separation (PCS). This study was approved by the Medical Ethics Committee of Shandong Maternal and Child Health Care Hospital (Ethics No. 2024-034).
RESULTS:
Both fetuses exhibited structural brain anomalies and developmental delays during the second trimester. Amniocyte karyotyping revealed low-level mosaic aneuploidy involving multiple chromosomes, while chromosomal microarray analysis (CMA) showed no abnormalities. Pregnancy termination was performed for fetus 1. WES identified compound heterozygous variants in BUB1B, i.e., c.2363_2364del (p.S788Cfs*29) and ss804270619: G>A, in both fetuses. Sanger sequencing confirmed paternal inheritance of c.2363_2364del and maternal inheritance of ss804270619:G>A. According to the American College of Medical Genetics and Genomics (ACMG) and Clinical Genome Resource (ClinGen) Standards and Guidelines for the Interpretation of Sequence Variants, the c.2363_2364del variant was classified as likely pathogenic (PVS1 + PM2_Supporting). Parental karyotyping demonstrated PCS traits, with a higher proportion of abnormal metaphases in the father.
CONCLUSION
The compound heterozygous variants c.2363_2364del (p.S788Cfs*29) and ss804270619: G>A in BUB1B may constitute the genetic etiology of the two MVA fetuses in this pedigree.
Humans
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Female
;
Pregnancy
;
Adult
;
Mosaicism
;
Protein Serine-Threonine Kinases/genetics*
;
Chromosome Disorders/diagnosis*
;
Pedigree
;
Heterozygote
;
Prenatal Diagnosis
;
Aneuploidy
;
Male
;
Fetus
;
Karyotyping
8.Genetic analysis of four individuals harboring a 16q22 fragile site.
Xiaoxiao HUANG ; Rong QIANG ; Yuan LIU ; Xue BAI ; Shuxian LI ; Qiujie JIN ; Qingting BU
Chinese Journal of Medical Genetics 2025;42(4):500-504
OBJECTIVE:
To analyze four patients with a 16q22 fragile site with miscarriage or infertility by using cytogenetic methods.
METHODS:
Four patients presented at Northwest Women's and Children's Hospital between January 2022 and December 2024 were selected as the study subjects. Peripheral blood samples were collected from the patients and subjected to G-banded chromosomal karyotyping, among whom two were also subjected to copy number variation (CNV) sequencing. This study has been approved by the Ethics Committee of the Hospital (Ethics No. 2020-022).
RESULTS:
The chromosomal karyotypes of the patients were mos 46,XX,fra(16)(q22)[26]/47,XX,del(16)(q22),+chrb(16)(q22)[4]/46,XX,del(16)(q22)[3]/46,XX[91], mos 46,XY,fra(16)(q22)[21]/46,XY,del(16)(q22)[3]/46,XY[76], mos 46,XX,fra(16)(q22)[21]/ 46,XX,del(16)(q22)[4]/46,XX[75] and mos 46,XX,fra(16)(q22)[16]/46,XX,del(16)(q22)[7]/47,XX,del(16)(q22),+chrb(16)(q22)[6]/47,XX,fra(16)(q22),+chrb(16)(q22)[3]/46,XX[68], respectively. CNV sequencing of patients 2 and 4 revealed no deletion or duplication on chromosome 16.
CONCLUSION
Identification of the 16q22 fragile site has facilitated genetic counseling for these patients.
Humans
;
Chromosome Fragile Sites/genetics*
;
Chromosomes, Human, Pair 16/genetics*
;
DNA Copy Number Variations/genetics*
;
Karyotyping
9.Prenatal diagnosis and analysis of fetuses with false-positive NIPT results caused by sex chromosomal abnormalities in pregnant women.
Tingting BAI ; Fengni FAN ; Lihui YANG ; Xiangdong LIN ; Rong QIANG ; Ting JIA ; Rui WANG
Chinese Journal of Medical Genetics 2025;42(5):525-531
OBJECTIVE:
To analyze the results of prenatal diagnosis for fetuses with a high risk for sex chromosome aneuploidies (SCAs) indicated by non-invasive prenatal testing (NIPT), and to assess the influence of maternal chromosomal factors on the results of NIPT.
METHODS:
A retrospective analysis was conducted on the clinical data of 454 pregnant women with a high risk for SCAs indicated by NIPT undergoing invasive prenatal diagnosis at the Medical Genetics Center of Northwest Women's and Children's Hospital from January 2022 to September 2024. The data has included prenatal diagnosis indications, results, pregnancy outcomes, and the chromosomal results of pregnant women.
RESULTS:
Among the 454 women (including 10 with twin pregnancy) with a high risk for SCAs indicated by NIPT, 149 (including 4 twin cases) were diagnosed with SCAs through invasive prenatal diagnosis. These had included 47,XXX (37 cases), 47,XXY (56 cases), 47,XYY (29 cases), 45,X (1 case), 48,XXYY (1 case), mosaicism (20 cases), sex chromosome structural abnormalities (6 cases), and small-scale pathogenic copy number variations (3 cases). 383 pregnant women (including 7 with twin pregnancy) had accepted chromosomal karyotyping analysis. In total 49 cases of SCAs abnormalities were detected. Among them, 41 cases were pregnant women with SCAs but normal fetal chromosomes, which yielded a false positive rate for NIPT caused by maternal factors by 10.7%. In addition, 8 cases (including 1 twin case) had SCAs abnormalities in both the pregnant woman and the fetus. Among the 383 pregnant women, 129 cases (including 3 twin cases) of fetal SCAs were diagnosed, which yielded an overall positive predictive value (PPV) of NIPT for SCAs by 33.7% (129/383). With the 41 false positive cases caused by maternal SCAs abnormalities excluded, the PPV of NIPT for SCAs will be increased to 37.7% (129/342). Among the 454 pregnant women, twin pregnancies have accounted for 2.2% (10/454). Among the confirmed cases of SCAs abnormalities, twin cases accounted for 2.7% (4/149). Among the 383 pregnant women undergoing chromosomal karyotyping, twin cases accounted for 1.8% (7/383). Among the detected cases of chromosomal abnormalities, twin cases accounted for 2.0% (1/49). By calculation, the proportion of singleton pregnant women with a high risk for SCAs indicated by NIPT was approximately 32.1%, and the proportion of twin pregnant women was approximately 38.6%, indicating that twin pregnancies could increase the positive rate of NIPT.
CONCLUSION
NIPT can improve the screening efficiency for SCAs, but its PPV is limited. Therefore, pregnant women with a high risk for SCAs indicated by NIPT need to undergo invasive prenatal diagnosis for a definite diagnosis, and twin pregnancies can increase the positive rate of NIPT. The study confirmed that chromosomal abnormalities in pregnant women can significantly affect the accuracy of NIPT in detecting fetal SCAs. Therefore, when NIPT indicates SCAs abnormalities, it is recommended to simultaneously conduct chromosomal testing on the pregnant women. The combined application of chromosomal karyotyping analysis, fluorescence in situ hybridization, and copy number variation detection techniques can significantly improve the diagnostic accuracy for SCAs, especially for the detection of mosaicisms.
Humans
;
Female
;
Pregnancy
;
Sex Chromosome Aberrations
;
Adult
;
Retrospective Studies
;
False Positive Reactions
;
Prenatal Diagnosis/methods*
;
Noninvasive Prenatal Testing/methods*
;
Aneuploidy
;
Male
;
Sex Chromosome Disorders/genetics*
10.Clinical and genetic analysis of four patients with Phelan-McDermid syndrome due to variants of SHANK gene.
Liangqiong DENG ; Xuan ZENG ; Linyan LIAO ; Xiaobo XIONG ; Aiwen LI ; Yan MEI ; Liujuan ZHANG ; Dejian YUAN
Chinese Journal of Medical Genetics 2025;42(5):563-567
OBJECTIVE:
To explore the clinical phenotype and genetic characteristics of four patients with Phelan-McDermid syndrome (PMS) due to variants of SHANK3 gene.
METHODS:
Four patients diagnosed with PMS at Guangzhou Women and Children's Medical Center Liuzhou Hospital from January 2020 to January 2025 were selected as the study subjects. Clinical data of the patients were collected. Peripheral venous blood samples were collected from each patient for the extraction of genomic DNA, followed by whole-exome sequencing (WES) and validation by Sanger sequencing. Pathogenicity of candidate variants was rated based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), and multiple bioinformatic tools were used to assess the pathogenic effects of the variants. The study was approved by the Ethics Committee of the Hospital (Ethics No. 2025-007).
RESULTS:
All four patients had exhibited language delay and intellectual disability (IQ 35 ~ 65). Some also presented with autism spectrum disorder and schizophrenia, albeit with significant phenotypic heterogeneity. All patients were found to harbor deletions of 22q13.33 region, ranging from 55.46 Kb to 112.64 Kb, primarily involving the SHANK3 gene.
CONCLUSION
PMS is typically caused by deletions or mutations of the SHANK3 gene. The clinical manifestations are diverse, with developmental delay and intellectual disability being the most common. Accurate diagnosis requires integration of genetic testing and standardized clinical assessment. Genetic screening for suspected patients and at-risk pregnant women is recommended to facilitate their genetic counseling.
Child
;
Humans
;
Chromosome Deletion
;
Chromosome Disorders/genetics*
;
Chromosomes, Human, Pair 22/genetics*
;
Exome Sequencing
;
Nerve Tissue Proteins/genetics*
;
Phenotype

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