1.Analysis of a fetus with unbalanced translocation derived from a balanced t(6;14) maternal translocation.
Mengting ZHANG ; Hai XIAO ; Dong WU ; Hongdan WANG ; Yue GAO ; Qian ZHANG ; Fengyang WANG ; Tao WANG ; Shixiu LIAO
Chinese Journal of Medical Genetics 2023;40(2):230-233
OBJECTIVE:
To explore the genetic characteristics of a fetus with a high risk by maternal serum screening during the second trimester.
METHODS:
Genetic counseling was provided to the pregnant woman on March 22, 2020 at Henan Provincial People's Hospital. G-banded chromosomal karyotyping and array comparative genomic hybridization (aCGH) were carried out on the amniotic fluid sample and peripheral blood samples from the couple.
RESULTS:
The fetus and the pregnant woman were respectively found to have a 46,XX,der(6)t(6;14)(q27;q31.2) and 46,XX,t(6;14)(q27;q31.2) karyotype, whilst the husband was found to have a normal karyotype. aCGH analysis has identified a 6.64 Mb deletion at 6q26q27 and a 19.98 Mb duplication at 14q31.3q32.33 in the fetus, both of which were predicted to be pathogenic copy number variations. No copy number variation was found in the couple.
CONCLUSION
The unbalanced chromosome abnormalities in the fetus have probably derived from the balanced translocation carried by the pregnant woman. aCGH can help to determine the types of fetal chromosome abnormalities and site of chromosomal breakage, which may facilitate the prediction of fetal outcome and choice for subsequent pregnancies.
Pregnancy
;
Female
;
Humans
;
Comparative Genomic Hybridization
;
DNA Copy Number Variations
;
Translocation, Genetic
;
Chromosome Aberrations
;
Fetus
;
Prenatal Diagnosis
2.Clinical and genetic analysis of two children with intellectual developmental disorder and microcephaly with pontine and cerebellar hypoplasia.
Na QI ; Ke YANG ; Xingxing LEI ; Fengyang WANG ; Dong WU ; Yue GAO ; Yuwei ZHANG ; Shixiu LIAO
Chinese Journal of Medical Genetics 2023;40(4):408-412
OBJECTIVE:
To explore the clinical features and genetic etiology of two children with intellectual developmental disorder and microcephaly with pontine and cerebellar hypoplasia (MICPCH).
METHODS:
Two children with MICPCH who were presented at the Henan Provincial People's Hospital between April 2019 and December 2021 were selected as the study subjects. Clinical data of the two children were collected, along with peripheral venous blood samples of them and their parents, and amniotic fluid sample of the mother of child 1. Whole exome sequencing (WES), array-comparative genomic hybridization (aCGH) and real-time quantitative PCR (qPCR) were carried out for the children, their parents and the fetus. The pathogenicity of candidate variants were evaluated.
RESULTS:
Child 1 was a 6-year-old girl featuring motor and language delay, whilst child 2 was a 4.5-year-old girl mainly featuring microcephaly and mental retardation. WES revealed that child 2 has harbored a 158.7 kb duplication in Xp11.4 (chrX: 41446160_41604854), which has encompassed exons 4~14 of the CASK gene. The same duplication was not found in either of her parents. aCGH revealed that child 1 has harbored a 29 kb deletion at Xp11.4 (chrX: 41637892_41666665), which encompassed exon 3 of the CASK gene. The same deletion was not found in either of her parents and the fetus. The above results were confirmed by qPCR assay. Above deletion and duplication were not found in the ExAC, 1000 Genomes and gnomAD databases. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), both variants were rated as likely pathogenic (PS2+PM2_Supporting).
CONCLUSION
The deletion of exon 3 and duplication of exons 4~14 of the CASK gene probably underlay the pathogenesis of MICPCH in these two children, respectively.
Humans
;
Child
;
Female
;
Child, Preschool
;
Microcephaly/genetics*
;
Developmental Disabilities/genetics*
;
Intellectual Disability/complications*
;
Comparative Genomic Hybridization
;
Mutation
3.Prenatal genetic analysis of a fetus with Miller-Dieker syndrome.
Fengyang WANG ; Na QI ; Tao WANG ; Yue GAO ; Dong WU ; Mengting ZHANG ; Ke YANG ; Huijuan PENG ; Xingxing LEI ; Shixiu LIAO
Chinese Journal of Medical Genetics 2023;40(4):505-511
OBJECTIVE:
To explore the genetic basis for fetus with bilateral lateral ventriculomegaly.
METHODS:
Fetus umbilical cord blood and peripheral blood samples of its parents were collected. The fetus was subjected to chromosomal karyotyping, whilst the fetus and its parents were subjected to array comparative genomic hybridization (aCGH). The candidate copy number variation (CNV) were verified by qPCR, Application goldeneye DNA identification system was used to confirm the parental relationship.
RESULTS:
The fetus was found to have a normal karyotype. aCGH analysis indicated that it has carried a 1.16 Mb deletion at 17p13.3, which partially overlapped with the critical region of Miller-Dieker syndrome (MDS), in addition with a 1.33 Mb deletion at 17p12 region, which is associated with hereditary stress-susceptible peripheral neuropathy (HNPP). Its mother was also found to harbor the 1.33 Mb deletion at 17p12. qPCR analysis confirmed that the expression levels of genes from the 17p13.3 and 17p12 regions were about the half of that in the normal control, as well as the maternal peripheral blood sample. Parental relationship was confirmed between the fetus and its parents. Following genetic counseling, the parents has chosen to continue with the pregnancy.
CONCLUSION
The fetus was diagnosed with Miller-Dieker syndrome due to the de novo deletion at 17p13.3. Ventriculomegaly may be an important indicator for prenatal ultrasonography in fetuses with MDS.
Pregnancy
;
Female
;
Humans
;
Classical Lissencephalies and Subcortical Band Heterotopias
;
Comparative Genomic Hybridization
;
DNA Copy Number Variations
;
Fetus
;
Hydrocephalus
;
Prenatal Diagnosis
;
Chromosome Deletion
4.Genetic analysis of two children with developmental delay and intellectual disability.
Fengyang WANG ; Na QI ; Yue GAO ; Dong WU ; Mengting ZHANG ; Qian ZHANG ; Ke YANG ; Huijuan PENG ; Xingxing LEI ; Shixiu LIAO
Chinese Journal of Medical Genetics 2023;40(7):876-880
OBJECTIVE:
To explore the genetic etiology of two patients with developmental delay and intellectual disability.
METHODS:
Two children who were respectively admitted to Henan Provincial People's Hospital on August 29, 2021 and August 5, 2019 were selected as the study subjects. Clinical data were collected, and array comparative genomic hybridization (aCGH) was carried out on the children and their parents for the detection of chromosomal microduplication/microdeletions.
RESULTS:
Patient 1 was a 2-year-and-10-month female and patient 2 was a 3-year-old female. Both children had featured developmental delay, intellectual disability, and abnormal findings on cranial MRI. aCGH revealed that patient 1 has harbored arr[hg19] 6q14.2q15(84621837_90815662)×1, a 6.19 Mb deletion at 6q14.2q15, which encompassed ZNF292, the pathogenic gene for Autosomal dominant intellectual developmental disorder 64. Patient 2 has harbored arr[hg19] 22q13.31q13.33(46294326_51178264)×1, a 4.88 Mb deletion at 22q13.31q13.33 encompassing the SHANK3 gene, haploinsufficiency of which can lead to Phelan-McDermid syndrome. Both deletions were classified as pathogenic CNVs based on the guidelines of American College of Medical Genetics and Genomics (ACMG) and were not found in their parents.
CONCLUSION
The 6q14.2q15 deletion and 22q13-31q13.33 deletion probably underlay the developmental delay and intellectual disability in the two children, respectively. Haploinsufficiency of the ZNF292 gene may account for the key clinical features of the 6q14.2q15 deletion.
Humans
;
Child
;
Female
;
Child, Preschool
;
Intellectual Disability/genetics*
;
Comparative Genomic Hybridization
;
Chromosome Disorders/genetics*
;
Chromosome Deletion
;
Magnetic Resonance Imaging
;
Chromosomes, Human, Pair 22
;
Developmental Disabilities/genetics*
;
Carrier Proteins/genetics*
;
Nerve Tissue Proteins/genetics*
5.Genetic analysis of a fetus with mosaicism of 13q inversion duplication.
Tingting LUO ; Ming CHE ; Dehua CHENG ; Lifang ZHANG ; Tao ZHANG ; Yan ZENG
Chinese Journal of Medical Genetics 2022;39(1):76-80
OBJECTIVE:
To report on a case of mosaicism 13q inversion duplication, analyze its mechanism, and discuss the correlation between its genotype and phenotype.
METHODS:
Amniotic fluid and umbilical cord blood were collected at 23 and 32 weeks of gestation, respectively. Combined with G-banding chromosome karyotyping analysis, single nucleotide polymorphism array (SNP-array) and fluorescence in situ hybridization (FISH) were used to confirm the result.
RESULTS:
The karyotype of the fetus was determined as 47,XY,+inv dup(13)(q14.3q34)/46,XY. After careful counseling, the couple decided to continue with the pregnancy, and had given birth to a boy at 40 weeks' gestation. Except for a red plaque (hemangioma) on the nose bridge, no obvious abnormality (intelligence to be evaluated) was discovered.
CONCLUSION
To provide reference for clinical genetic counseling and risk assessment, the location and proportion of new centromere formation should be fully considered in the case of mosaicism 13q inversion duplication.
Amniocentesis
;
Chromosome Inversion/genetics*
;
Comparative Genomic Hybridization
;
Female
;
Fetus
;
Humans
;
In Situ Hybridization, Fluorescence
;
Male
;
Mosaicism
;
Pregnancy
;
Prenatal Diagnosis
6.Genetic analysis of a case with mosaicism of a small supernumerary marker chromosome derived from idic(15).
Minjie SHAO ; Yun WANG ; Nan ZHAO ; Ping LIU
Chinese Journal of Medical Genetics 2022;39(1):85-88
OBJECTIVE:
To determine the origin of a mosaicism small supernumerary marker chromosome (sSMC) by cytogenetic and molecular analysis.
METHODS:
Karyotype analysis, fluorescence in situ hybridization (FISH) and SNP-array were carried out.
RESULTS:
The karyotype of the patient was mos47,XX,+mar[45]/48,XX,+2mar[3]/46,XX[52]; the SNP-array result was arr[hg19]15q11.1q11.2 (20 161 372-24 314 675)×3, and the repeat fragment was about 4.15 Mb. FISH showed that approximately 50% of the cells have contained a sSMC with double D15Z1 probe site segments derived from abnormal idic(15). This sSMC did not contain SNRPN and PML probe fragments of Prader-Willi syndrome/Angelman syndrome.
CONCLUSION
When the patient's karyotype and phenotype are inconsistent, cytogenetic and molecular biology technologies should be combined to clarify the karyotype and gene location, so as to provide more accurate genetic consultation for the follow-up treatments.
Chromosome Disorders
;
Chromosomes, Human, Pair 15
;
Comparative Genomic Hybridization
;
Humans
;
In Situ Hybridization, Fluorescence
;
Karyotype
;
Mosaicism
7.Genetic research progress in branchio-oto syndrome/ branchio-oto-renal syndrome.
Anhai CHEN ; Jie LING ; Yong FENG
Journal of Central South University(Medical Sciences) 2022;47(1):129-138
Branchio-oto syndrome (BOS)/branchio-oto-renal syndrome (BORS) is a kind of autosomal dominant heterogeneous disorder. These diseases are mainly characterized by hearing impairment and abnormal phenotype of ears, accompanied by renal malformation and branchial cleft anomalies including cyst or fistula, with an incidence of 1/40 000 in human population. Otic anormalies are one of the most obvious clinical manifestations of BOS/BORS, including deformities of external, middle, inner ears and hearing loss with conductive, sensorineural or mix, ranging from mild to profound loss. Temporal bone imaging could assist in the diagnosis of middle ear and inner ear malformations for clinicians. Multiple methods including direct sequencing combined with next generation sequencing (NGS), multiplex ligation-dependent probe amplification (MLPA), or array-based comparative genomic hybridization (aCGH) can effectively screen and identify pathogenic genes and/or variation types of BOS/BORS. About 40% of patients with BOS/BORS carry aberrations of EYA1 gene which is the most important cause of BOS/BORS. A total of 240 kinds of pathogenic variations of EYA1 have been reported in different populations so far, including frameshift, nonsense, missense, aberrant splicing, deletion and complex rearrangements. Human Endogenous Retroviral sequences (HERVs) may play an important role in mediating EYA1 chromosomal fragment deletion mutations caused by non-allelic homologous recombination. EYA1 encodes a phosphatase-transactivator cooperated with transcription factors of SIX1, participates in cranial sensory neurogenesis and development of branchial arch-derived organs, then regulates the morphological and functional differentiation of the outer ear, middle ear and inner ear toward normal tissues. In addition, pathogenic mutations of SIX1 and SIX5 genes can also cause BOS/BORS. Variations of these genes mentioned above may cause disease by destroying the bindings between SIX1-EYA1, SIX5-EYA1 or SIX1-DNA. However, the role of SIX5 gene in the pathogenesis of BORS needs further verification.
Branchio-Oto-Renal Syndrome/pathology*
;
Chromosome Deletion
;
Comparative Genomic Hybridization
;
Genetic Research
;
Homeodomain Proteins/genetics*
;
Humans
;
Intracellular Signaling Peptides and Proteins
;
Nuclear Proteins/metabolism*
;
Pedigree
;
Protein Tyrosine Phosphatases/metabolism*
8.Advances in identification methods of alien genomic components in plants.
Zhongyi XIE ; Jiangbo DANG ; Guo WEN ; Haiyan WANG ; Qigao GUO ; Guolu LIANG
Chinese Journal of Biotechnology 2021;37(8):2703-2718
Plants with alien genomic components (alien chromosomes / chromosomal fragments / genes) are important materials for genomic research and crop improvement. To date, four strategies based on trait observation, chromosome analysis, specific proteins, and DNA sequences have been developed for the identification of alien genomic components. Among them, DNA sequence-based molecular markers are mainly used to identify alien genomic components. This review summarized several molecular markers for identification of alien genomic components in wheat, cabbage and other important crops. We also compared the characteristics of nine common molecular markers, such as simple sequence repeat (SSR), insertion-deletion (InDel) and single nucleotide polymorphism (SNP). In general, the accuracy of using a combination of different identification methods is higher than using a single identification method. We analyzed the application of different combination of identification methods, and provided the best combination for wheat, brassica and other crops. High-throughput detection can be easily achieved by using the new generation molecular markers such as InDel and SNP, which can be used to determine the precise localization of alien introgression genes. To increase the identification efficiency, other new identification methods, such as microarray comparative genomic hybridization (array-CGH) and suppression subtractive hybridization (SSH), may also be included.
Chromosomes, Plant
;
Comparative Genomic Hybridization
;
Genome, Plant/genetics*
;
Genomics
;
Triticum/genetics*
9.Genetic analysis of a case with Pierre-Robin sequence due to partial 1q trisomy and partial 4q monosomy.
Qiuyan ZHANG ; Shanshan GAO ; Li WANG ; Panlai SHI ; Xiangdong KONG
Chinese Journal of Medical Genetics 2021;38(4):369-372
OBJECTIVE:
To explore the genetic basis for a neonate with Pierre-Robin sequence.
METHODS:
The child was subjected to chromosomal karyotyping, single nucleotide polymorphism array (SNP-array)-based comparative genomic hybridization and fluorescence in situ hybridization (FISH) analysis.
RESULTS:
The child has featured microgthnia, glossoptosis, upper airway obstruction, mandible dehiscence and short neck. He was found to have a karyotype of 46,XY,der(4)add(4)(q34). Her mother's karyotype was determined as 46,XX,t(1;4)(q43;q34), while his father was 46,XY. SNP-array analysis suggested the child to be arr [hg19] 1q42.2q44 (232 527 958-249 202 755)× 3; 4q34.3q35.2 (168 236 901-190 880 409)× 1. The result of SNP-array for both parents was normal. FISH analysis confirmed that his mother has carried a balanced t(1;4)(q42;34) translocation. The aberrant chromosome 4 in the child has derived from his mother's translocation, which gave rise to partial 1q trisomy and 4q monosomy.
CONCLUSION
The 1q42.2q44 duplication and 4q34.3q35.2 deletion of the child probably underlay his abnormal phenotype of Pierre-Robin sequence.
Child
;
Comparative Genomic Hybridization
;
Female
;
Humans
;
In Situ Hybridization, Fluorescence
;
Infant, Newborn
;
Male
;
Monosomy
;
Pierre Robin Syndrome/genetics*
;
Translocation, Genetic
;
Trisomy/genetics*
10.Advance in research on microdeletion/microduplications at Xp22.3.
Chinese Journal of Medical Genetics 2020;37(5):584-587
With the application of BACs-on-Beads (BoBs) and array-comparative genome hybridization (aCGH) technologies in prenatal diagnosis, microdeletion/microduplications at Xp22.3 have been frequently detected. However, the relatively high prevalence and lack of knowledge of such disorders have brought difficulties for clinical genetic counseling. Here, recent progress of research on microdeletion/microduplications at Xp22.3, including epidemiology, pathogenesis, clinical manifestation, and prenatal diagnosis, is reviewed.
Chromosomes, Human, X
;
genetics
;
Comparative Genomic Hybridization
;
Female
;
Genetic Counseling
;
Humans
;
Karyotyping
;
Pregnancy
;
Prenatal Diagnosis
;
Research
;
trends

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