1.Clinical and genetic analysis of a child with 46,XX male phenotype due to SOX3 gene duplication.
Xiou WANG ; Fuying SONG ; Ziqin LIU ; Pengchao WANG ; Mu DU ; Yi SONG ; Shuyue HUANG ; Bingyan CHAO
Chinese Journal of Medical Genetics 2026;43(1):50-56
OBJECTIVE:
To summarize the clinical and genetic characteristics of a child with 46,XX Ovotesticular disorder of sex development (46,XX OTDSD) due to copy number variation of SOX3 gene.
METHODS:
A 46,XX male patient presented at the Capital Center for Children's Health, Capital Medical University in November 2024 was selected as the study subject. Clinical data of the child was collected. Peripheral blood samples were taken from the child and his parents and subjected to trio whole-genome sequencing. Skewed X-chromosome inactivation was tested in the child and his mother. A literature review was carried out on 46,XX males associated with mutations of the SOX3 gene. This study was approved by the Medical Ethics Committee of the Hospital (Ethics No.: SHERLL2025056).
RESULTS:
The 10-year-old boy presented with hypospadias and cryptorchidism at birth. Chromosome analysis at one year and a half revealed a 46,XX karyotype. Gonadal biopsy showed testicular tissue, while ultrasound at the age of 10 detected ovotesticular tissue. Whole-genome sequencing identified a 660 kb duplication in the Xq27.1 region, which was derived from his mother. X-chromosome inactivation testing showed random inactivation in the child and mild non-random inactivation in the mother. Literature review has found 11 publications involving 15 patients (including our case), among whom 14 had a male social gender. They had primarily presented with hypospadias at birth but had no significant endocrine abnormalities. Most patients had experienced testicular failure after puberty. SOX3 related 46,XX males are mainly caused by de novo duplications, although a few maternal carriers had been discovered.
CONCLUSION
Duplication of the SOX3 gene probably underlay the pathogenesis is this 46,XX male. Individuals with 46,XX SRY negative male phenotypes should be routinely screened for SOX3 gene variants. Structural variations of the SOX3 gene can lead to complete or partial sex reversal in 46,XX individuals with minimal impact on intellectual and motor development, as well as other endocrine hormones.
Child
;
Humans
;
Male
;
46, XX Disorders of Sex Development/genetics*
;
DNA Copy Number Variations
;
Gene Duplication
;
Phenotype
;
SOXB1 Transcription Factors/genetics*
2.Precise identification of a cryptic balanced translocation in a couple with recurrent spontaneous abortions using C-MoKa technique.
Rui FAN ; Yaru LIU ; Tingting JI ; Xiaojuan XU ; Xuening DING ; Xiaoling MA
Chinese Journal of Medical Genetics 2026;43(1):64-69
OBJECTIVE:
Chromosome conformation-based karyotype analysis (C-MoKa) technology was used to test a couple who had experienced multiple adverse pregnancies in order to provide them with genetic counseling and reproductive guidance.
METHODS:
A couple presented at the Reproductive Medicine Center of the First Hospital of Lanzhou University in 2023 was selected as the study subject. Through C-MoKa testing, copy number variation sequencing (CNV-seq), and preimplantation genetic testing for aneuploidy (PGT-A), it was found that the couple's repeatedly miscarried fetuses and abnormal embryos exhibited highly similar chromosomal structural abnormalities. Using C-MoKa, the potential genetic abnormalities in both partners were traced, and reproductive guidance was provided based on the result. This study was approved by the Medical Ethics Committee of the Hospital (Ethics No.: LDYYSZLLKH2025-09).
RESULTS:
CNV-seq analysis of the couple's miscarriage fetal chorionic villi showed del(18)(q21.2q23)(28.90 Mb) and dup(13)(q31.2q34)(26.26 Mb). Chromosomal karyotyping analysis of both partners showed no abnormality. From 2024 to 2025, the couple underwent three rounds of PGT-A assisted reproduction. The first embryo test showed del(13)(q31.2q34)(26.77 Mb) and dup(18)(q21.2q23)(29.08 Mb). The second embryo test showed dup(13)(q31.2q34)(26.26 Mb) and del(18)(q21.2q23)(28.90 Mb). And the third embryo test results showed complex chromosomal abnormalities. In 2025, after genetic counseling, the couple had opted C-MoKa test, which has detected no abnormality in the wife, but a balanced 46,XY,t(13;18)(q31.2;q21.2) translocation in the husband.
CONCLUSION
As a high-throughput sequencing method based on the three-dimensional conformation of chromatin, C-MoKa has the advantages of high resolution and high accuracy, and can accurately detect balanced translocations with similar banding patterns. It has therefore offered a powerful new tool for chromosomal analysis.
Female
;
Humans
;
Male
;
Pregnancy
;
Abortion, Habitual/genetics*
;
DNA Copy Number Variations
;
Karyotyping/methods*
;
Preimplantation Diagnosis
;
Translocation, Genetic
3.Genetic analysis and prenatal diagnosis of structural brain abnormalities associated with TUBB gene c.155A>G variant.
Yifan LIU ; Wei SONG ; Xinlian WANG ; Yan RUAN ; Meng ZHANG ; Yujiao CHEN ; Yan LIU ; Puqing ZHANG ; Li WANG ; Yousheng YAN
Chinese Journal of Medical Genetics 2026;43(2):136-142
OBJECTIVE:
To explore the genotype-phenotype correlation in a Chinese family with structural brain abnormalities due to variant of the TUBB gene.
METHODS:
A family undergoing prenatal diagnosis at Beijing Obstetrics and Gynecology Hospital in October 2024 was selected as the study subject. Clinical data were collected. Amniotic fluid sample was subjected to chromosomal copy number variation sequencing (CNV-seq). Trio whole-exome sequencing (Trio-WES) was carried out on the amniotic fluid and parental blood samples, and candidate variant was verified by Sanger sequencing. This study was approved by the Medical Ethics Committee of the hospital (Ethics No.: 2023-KY-076-01).
RESULTS:
Both prenatal ultrasound and fetal MRI showed deviation of brain midline, unilateral lateral ventriculomegaly, and bilateral gyral asymmetry. Trio-WES revealed that the fetus has harbored a maternally derived heterozygous missense variant of the TUBB gene [NM_178014.4: c.155A>G (p.N52S)]. Sanger sequencing confirmed that the woman and a previously terminated fetus both harbored the same variant. Both the proband and two fetuses exhibited similar neuroimaging abnormalities including midline deviation and asymmetrical gyri. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was classified as likely pathogenic (PM2_Supporting+PS2_Moderate+PS3).
CONCLUSION
The heterozygous c.155A>G (p.N52S) variant was the TUBB gene probably underlay the pathogenesis of the structural brain abnormalities in this family. Above findings have expanded the phenotypic spectrum associated with the variant and facilitated the prenatal diagnosis for this family.
Humans
;
Female
;
Pregnancy
;
Prenatal Diagnosis
;
Tubulin/genetics*
;
Adult
;
Brain/diagnostic imaging*
;
Male
;
Pedigree
;
DNA Copy Number Variations/genetics*
;
Exome Sequencing
;
Genetic Association Studies
;
Magnetic Resonance Imaging
4.Analysis of ten cases of Acute lymphoblastic leukemia with non-KMT2A::AFF1 transcriptional variant 11q23 rearrangements.
Yuanyuan WANG ; Shuzhen FU ; Yong SHEN ; Qingxia XU
Chinese Journal of Medical Genetics 2026;43(4):265-272
OBJECTIVE:
To analyze the clinical characteristics of patients with 11q23 rearrangement acute lymphoblastic leukemia (ALL) with non-KMT2A::AFF1 fusion genes.
METHODS:
The clinical data of 10 patients with KMT2A fusion gene positive and partner gene non-AFF1 ALL admitted to Henan Cancer Hospital from December 2016 to December 2024 were retrospectively summarized. The immunophenotype, molecular genetic characteristics, clinical manifestations and disease prognosis of these patients were analyzed. This research has been approved by the Medical Ethics Committee of Henan Cancer Hospital (Ethics No.: 2019342).
RESULTS:
Among the 10 patients, the fusion genes were KMT2A::MLLT1 in 7 cases, KMT2A::MLLT4, KMT2A::MLLT3 and KMT2A::MLLT10 in 1 case each. The European Group for the Immunological Classification of Leukemias (EGIL) classification included 6 cases of T-ALL, 2 cases of pro-B-ALL, 1 case of Common-B-ALL and 1 case of pre-B-ALL. 4 cases of B-ALL all expressed CD19, cCD79a, CD38 and HLA-DR, and some expressed CD34 and CD22, without expression or weak expression of CD10, without expression of CD20. One case was accompanied by myeloid marker CD15 expression. 6 cases of T-ALL all expressed CD34, CD7, most expressed CD38, and some expressed CD3, CD5, CD2, CD4 and CD8, and 1 case expressed CD4 and CD8 together. Chromosomal abnormalities were detected in 3 cases, 5 cases were positive for WT1 fusion gene, and 6 cases had gene alterations. 9 patients achieved the first complete remission (CR1) during chemotherapy, and 1 patient relapsed within 6 months after CR1. At the last follow up, 1 patient (the fusion gene was KMT2A::MLLT4) remained unrelieved. There were 2 cases of KMT2A rearrangement (KMT2A-r) persistent positive (+/+) and 8 cases of KMT2A-r negative (+/-). The overall survival (OS) rate and leukemia-free survival (LFS) rate of patients with KMT2A-r persistent positive were significantly lower than those of patients with negative change, and the differences were statistically significant (P values were all < 0.05). Among the 3 patients who received chemotherapy+allogeneic hematopoietic stem cell transplantation (allo-HSCT), no relapse was observed until the follow up day. The OS rate and LFS rate of patients with KMT2A::MLLT1 and chemotherapy+allo-HSCT were higher than those of non-KMT2A::MLLT1 and single chemotherapy patients, and the differences were not statistically significant (P values were all ≥ 0.05). There was no significant difference in OS rate and LFS rate between T-ALL and B-ALL patients (P values were all ≥ 0.05). The median LFS time of the 10 patients was 32 (0 ~ 100) months, and the median OS time was 36 (1 ~ 101) months.
CONCLUSION
The 11q23 rearrangement ALL with non-KMT2A::AFF1 transcript is mainly KMT2A::MLLT1, T-ALL is more common, and the rate of chromosomal karyotype detection is relatively low. Persistent positive KMT2A-r is unfavorable for patient survival, and allo-HSCT during the CR1 period may improve patient survival.
Humans
;
Precursor Cell Lymphoblastic Leukemia-Lymphoma/genetics*
;
Female
;
Male
;
Myeloid-Lymphoid Leukemia Protein/genetics*
;
Histone-Lysine N-Methyltransferase/genetics*
;
Adult
;
Adolescent
;
Chromosomes, Human, Pair 11/genetics*
;
Child
;
Transcriptional Elongation Factors/genetics*
;
Gene Rearrangement
;
Oncogene Proteins, Fusion/genetics*
;
Retrospective Studies
;
Young Adult
;
Middle Aged
;
Prognosis
;
Child, Preschool
;
DNA-Binding Proteins/genetics*
5.Genetic analysis of a de novo EFTUD2 variant causing Mandibulofacial dysostosis with microcephaly in a fetus.
Jianyu REN ; Xiaojiao GUAN ; Shuang LIU ; Yousheng YAN ; Shufa YANG
Chinese Journal of Medical Genetics 2026;43(4):288-294
OBJECTIVE:
To investigate the genetic etiology of a fetus diagnosed with Mandibulofacial dysostosis with microcephaly (MFDM).
METHODS:
A fetus that underwent prenatal diagnosis at Beijing Obstetrics and Gynecology Hospital, Capital Medical University, on May 19, 2025 was selected for analysis. Results of fetal ultrasound findings, chromosomal karyotyping, copy number variation sequencing (CNV-seq), and whole-exome sequencing (WES) were collected. Sanger sequencing was performed for familial validation of the pathogenic variant. The Human Protein Atlas (HPA), STRING, and Simple ClinVar databases were queried to characterize the biological features of the candidate gene. Three-dimensional structures of the wild-type and variant proteins were modeled and analyzed, and the evolutionary conservation of the affected amino acid was assessed using UGENE. Prenatal phenotypes associated with EFTUD2 variants were summarized through a review of the literature. This study was approved by the Ethics Committee of Beijing Obstetrics and Gynecology Hospital, Capital Medical University (Ethics No.: 2025-KY-029-01).
RESULTS:
At 23+2 weeks of gestation, ultrasound examination revealed bilateral microtia with low-set ears, mild micrognathia with a reduced mandibular-facial angle, a single umbilical artery, a slightly narrow aortic diameter, and trivial mitral regurgitation. Amniotic fluid karyotyping and CNV-seq showed no abnormalities. WES identified a de novo, previously unreported EFTUD2 variant, c.698dupA (p.V235Gfs*27), in the fetus. This frameshift variant is predicted to alter the structural integrity of the EFTUD2 protein. Literature review indicated that micrognathia and microtia or low-set ears are the most common sonographic features in fetuses with EFTUD2 variants, while secondary findings may include abnormal stomach bubble, cleft palate, single umbilical artery, gastrointestinal atresia, polyhydramnios, and reduced aortic diameter.
CONCLUSION
The EFTUD2: c.698dupA (p.V235Gfs*27) variant is likely the genetic cause underlying MFDM in this fetus.
Humans
;
Mandibulofacial Dysostosis/diagnostic imaging*
;
Microcephaly/diagnostic imaging*
;
Female
;
Pregnancy
;
Ribonucleoprotein, U5 Small Nuclear/chemistry*
;
Peptide Elongation Factors/chemistry*
;
Fetus
;
DNA Copy Number Variations/genetics*
;
Adult
;
Ultrasonography, Prenatal
6.Study of the feasibility of polar body transfer combined with preimplantation genetic testing for blocking the intergenerational transmission of mitochondrial genetic diseases.
Dongmei JI ; Zhikang ZHANG ; Weiwei ZOU ; Ning ZHANG ; Kai ZONG ; Yinan DU ; Xun SU ; Xin WANG ; Dawei CHEN ; Chunmei LIANG ; Zhiguo ZHANG ; Yunxia CAO
Chinese Journal of Medical Genetics 2025;42(1):18-25
OBJECTIVE:
To assess the feasibility of first polar body transfer (PB1T) combined with preimplantation mitochondrial genetic testing for blocking the transmission of a pathogenic mitochondrial DNA 8993T>G mutation.
METHODS:
A Chinese family affected with Leigh syndrome which had attended the Reproductive Medicine Centre of the First Affiliated Hospital of Anhui Medical University in September 2021 was selected as the study subject. Controlled ovarian hyperstimulation was carried out for the proband after completing the detection of the mitochondrial DNA 8993T>G mutation load among the pedigree members. Mature MII oocytes were inseminated by intracytoplasmic sperm injection (ICSI), cultured in vitro for 5 to 6 days to the blastocyst stage, and trophoblastocytes were obtained by microbiopsy. Mitochondrial DNA testing (PGT-MT) and chromosomal aneuploidy (PGT-A) analyses were carried out after whole-genome amplification, and the embryos with zero mutation load were selected for transfer. Amniotic fluid and umbilical cord blood samples were collected during middle pregnancy and after birth respectively for mitochondrial DNA testing to verify the reliability of embryo screening. As an attempt, PB1 with good morphology of MII oocytes was selected for transfer into the enucleated oocytoplasm from healthy donors, followed by ICSI fertilization, blastocyst culture and PGT of embryos using the same procedure. This study has been approved by the Ethics Committee of the First Affiliated Hospital of Anhui Medical University (No. 2021zhyx-B12).
RESULTS:
An antagonist protocol was used for ovarian stimulation, and a total of 19 oocytes were obtained, of which 14 MII were fertilized by ICSI, and 2 had developed into blastocysts. PGT-MT was carried out on biopsied trophoblastocytes, in which the mitochondrial DNA 8993T>G mutation load was not detected in one embryo, the other was 100% mutated, and the mutation loads of the remaining unfertilized eggs and developmentally arrested embryos ranged from 0% ~ 100%, presenting a clear biased distribution. With fully informed consent, one PGT-MT zero mutation load blastocyst was transferred and clinical pregnancy was achieved. Mitochondrial DNA and chromosomal testing of amniotic fluid cells during middle pregnancy had revealed no abnormalities. The proband had delivered a healthy boy through Caesarean section at 39+5 weeks of gestation, and no mutation was detected in the cord blood sample. Five well-formed PBs from 14 eggs were selected for PB1 transfer, followed by ICSI and culture, and two of the reconstituted embryos had formed blastocysts, with none of the above mutations detected in the biopsied samples.
CONCLUSION
The PGT-MT technology can help families affected with mitochondrial diseases to have healthy offspring. PB1 transfer in combination with ICSI and PGT-MT holds the promise of turning waste into treasure and providing an alternative means of fertility for such families.
Humans
;
Preimplantation Diagnosis/methods*
;
Female
;
DNA, Mitochondrial/genetics*
;
Genetic Testing/methods*
;
Pregnancy
;
Mitochondrial Diseases/genetics*
;
Polar Bodies
;
Adult
;
Feasibility Studies
;
Sperm Injections, Intracytoplasmic/methods*
;
Embryo Transfer/methods*
;
Mutation
;
Male
;
Blastocyst/metabolism*
;
Pedigree
7.Carrier screening and prenatal diagnosis for Spinal muscular atrophy in 17 926 women of reproductive age in Chongqing.
Xia CHEN ; Yang GAO ; Wenhong CHEN ; Xing LUO ; Keya TONG
Chinese Journal of Medical Genetics 2025;42(2):180-186
OBJECTIVE:
To assess the carrier frequency of spinal muscular atrophy (SMA) in women of childbearing age in Chongqing and to evaluate prenatal diagnostic outcomes in high-risk couples.
METHODS:
A total of 17 926 women of childbearing age attending Chongqing Health Center for Women and Children between May 2021 and November 2023 were enrolled, including 3 398 pre-pregnant women and 14 528 pregnant women, all of whom had no clinical phenotype or family history of SMA or related neuromuscular disorders. Real-time quantitative PCR (RT-qPCR) was used to determine the copy number variations in exons 7 and 8 (E7, E8) of the SMN1 gene. High-risk carriers were identified based on the genetic screening results. Multiplex ligation-dependent probe amplification (MLPA) was employed for prenatal diagnosis of fetuses from high-risk couples. This study was approved by the Medical Ethics Committee of Chongqing Health Center for Women and Children (Ethics No.2021-RGI-02).
RESULTS:
Among the 17 926 women of childbearing age, 298 (1.66%) were identified as heterozygous carriers, including 278 (1.55%) with concurrent deletions of E7 and E8, and 20 (0.11%) with isolated deletions of E7. Seven high-risk couples were identified, six of whom were prenatal couples. Of the two fetuses from these high-risk pregnancies, both exhibited heterozygous deletions of E7 and E8 in the SMN1 gene, while four fetuses showed no abnormalities.
CONCLUSION
This study provides a comprehensive assessment of the carrier frequency of SMA among women of childbearing age in Chongqing, offering valuable data for the primary and secondary prevention of SMA-related birth defects in the region.
Humans
;
Female
;
Muscular Atrophy, Spinal/diagnosis*
;
Pregnancy
;
Prenatal Diagnosis/methods*
;
Adult
;
Survival of Motor Neuron 1 Protein/genetics*
;
Genetic Carrier Screening/methods*
;
DNA Copy Number Variations/genetics*
;
China
;
Genetic Testing
;
Heterozygote
8.Preliminary analysis of mRNA m7G modifications in human Adenocarcinoma of esophagogastric junction.
Ziyan LIU ; Xiaoyan WANG ; Binbin HU ; Shiqi ZHANG ; Yakun LANG ; Yu FAN
Chinese Journal of Medical Genetics 2025;42(2):187-197
OBJECTIVE:
To explore the potential role of mRNA m7G modification in the pathogenesis of human adenocarcinoma of esophagogastric junction (AEG).
METHODS:
Pathological tissue specimens from four AEG patients who underwent surgical treatment at the People's Hospital Affiliated to Jiangsu University between 2018 and 2019 were selected. Tumor tissues and adjacent normal tissues were collected from these patients. RNA was extracted from both tissue types and subjected to m7G methylated RNA immunoprecipitation sequencing (m7G-MeRIP-seq) to analyze the patterns of m7G modification, the characteristics of differential m7G modification sites, the differentially expressed mRNA, and the correlation between m7G modification and mRNA expression levels. Differential m7G-modified genes (MSH6, BRCA1, and SOX9) were further validated using methylated RNA immunoprecipitation quantitative PCR (MeRIP-qPCR), while the expression of METTL1 and WDR4 genes was examined by real-time quantitative PCR (RT-qPCR). This study was approved by the Medical Ethics Committee of the People's Hospital Affiliated to Jiangsu University (Ethics No. 20150083).
RESULTS:
m7G-MeRIP-seq analysis revealed that m7G modifications in both AEG and adjacent normal tissues were predominantly located in the GC-rich region surrounding the internal start codon of mRNA. Differential m7G modification sites between the two groups were closely associated with cancer-related genes. mRNA library analysis showed that differentially expressed mRNA were predominantly upregulated in AEG tissues and downregulated in adjacent normal tissues. Cross-analysis indicated that genes with hypermethylation tended to exhibit upregulated expression, while genes with hypomethylation were typically downregulated in AEG tissues. MeRIP-qPCR validation confirmed that the mRNA expression of MSH6, BRCA1, and SOX9 were significantly upregulated in AEG tissues compared to adjacent normal tissues (AEG vs. normal, P < 0.05). RT-qPCR results demonstrated that the mRNA expression levels of METTL1 and WDR4 were also upregulated in AEG tissues (AEG vs. normal, P < 0.000 5).
CONCLUSION
These findings suggest that mRNA m7G modification plays a significant role in the development of AEG. Furthermore, proteins as METTL1 and WDR4 may facilitate AEG progression by regulating mRNA m7G modification. These results provide valuable insights into the molecular mechanisms underlying AEG and may inform future therapeutic strategies for this malignancy.
Humans
;
RNA, Messenger/metabolism*
;
Adenocarcinoma/pathology*
;
Esophagogastric Junction/metabolism*
;
Esophageal Neoplasms/metabolism*
;
Gene Expression Regulation, Neoplastic
;
Female
;
Male
;
Middle Aged
;
DNA Methylation
;
Methyltransferases/metabolism*
;
Stomach Neoplasms/genetics*
9.Clinical analysis of a child with heterotopic ventricular gray matter Renpenning syndrome caused by PQBP1 gene mutation and a literature review.
Yazhen FAN ; Jianchuang ZHAO ; Qian CHEN ; Xianjie HUANG ; Fan LI ; Junying QIAO
Chinese Journal of Medical Genetics 2025;42(3):314-321
OBJECTIVE:
To explore the genetic etiology of a child with Renpenning syndrome (RS), and review the literature on the clinical characteristics and gene mutations of RS.
METHODS:
A child with RS (patient 1) who was diagnosed and treated in the Pediatric Intensive Care Unit of the Third Affiliated Hospital of Zhengzhou University in November 2023 was selected as the research object. The medical history, family history, physical examination, cerebrospinal fluid examination, echocardiography, brain magnetic resonance imaging (MRI), brain magnetic resonance angiography, cardiac coronary CT angiography and intelligence quotient (IQ) score of child 1 were retrospectively collected. Peripheral venous blood samples were collected from patient 1, his parents, sister and brother, respectively. Genomic DNA was extracted from the child and his family members, and Trios-whole exome sequencing (Trios-WES) was performed. Sanger sequencing was used to verify the pedigree. Bioinformatics softwares (Mutation Taster, REVEL, SIFT, PolyPhen-2, GERP++, SWISS-MODEL) were applied. The pathogenicity of the detected variants was rated according to the American College of Medical Genetics and Genomics (ACMG) Standards and Guidelines for the Classification of Genetic Variants (hereinafter referred to as the ACMG Guidelines). "PQBP1 gene" "Renpenning syndrome" "PQBP1 gene" "Renpenning syndrome" were used as keywords in Chinese and English, respectively. Case reports of patients with RS caused by PQBP1 gene variants were retrieved from Wanfang Data Knowledge Service Platform, China National Knowledge Infrastructure and PubMed database. The clinical features and gene variants of RS caused by PQBP1 gene variants were summarized and analyzed. This study was reviewed by the Medical Ethics Committee of the Third Affiliated Hospital of Zhengzhou University (Approval No. 2024-334-01).
RESULTS
The patient 1, a 12-year-old boy, was admitted to the hospital due to fever and disturbance of consciousness. Cerebrospinal fluid test showed viral encephalitis caused by human herpesvirus 7 infection. The main clinical manifestations were unusual facies (microcephaly, long narrow face, microphthalmos, superior oblique palpebral fissure, hypertelorism of inner canthus, bulbous nasal columella) and mental retardation. Auxiliary examination showed than patient 1 had atrial septal defect, nodular heterotopia in the posterior horn of the left ventricle, angiodysplasia, and low IQ. The disease began in infancy, and there was no family history of related diseases. A hemizygous deletion, c.459_462del (p.Arg153SerfsTer41), was identified in exon 5 of the PQBP1 gene in patient 1, which was inherited from his mother by Sanger sequencing. The results of bioinformatics analysis showed that the mutation was harmful. This variant was rated as pathogenic (PVS1+PS4+PM2_Supporting+PP3) according to ACMG Guidelines. According to the literature search strategy set in this study, a total of 13 cases of RS were retrieved, involving 16 cases of RS patient caused by PQBP1 gene mutation (patients 2-17), including patient 1, a total of 17 cases of RS. Among the 17 patients, 16 male patients had hemizygous mutations in the X chromosome PQBP1 gene, and 1 female patient had heterozygous mutations, including 12 deletion frameshift nonsense mutations, 3 point missense mutations, and 2 duplication mutations. Except for two fetuses, all patients had special facial features and low IQ to varying degrees. Ten patients had abnormal development of one or more organs such as eyes, heart, brain, etc. CONCLUSION: The main clinical manifestations of RS are developmental delay, long narrow face, bulbous nose, microcephaly, and may be accompanied by heterotopia of gray matter of ventricle and congenital heart disease. The c.459_462del (p.Arg153SerfsTer41) variant of the PQBP1 gene is the genetic basis of patient 1 in this study.
Humans
;
Male
;
Mutation
;
Pedigree
;
Child
;
DNA-Binding Proteins/genetics*
;
Nuclear Proteins/genetics*
;
Female
;
Exome Sequencing
10.A case of complex structural variants in the Xq28 region diagnosed by whole genome sequencing.
Yulai YANG ; Chuang LI ; Ming GAO ; Yuan LYU
Chinese Journal of Medical Genetics 2025;42(3):355-359
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

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