1.Cytogenetic and molecular genetic analysis of three cases with small supernumerary marker chromosomes.
Jiaming FAN ; Yan ZENG ; Tingting LUO ; Ming CHE
Chinese Journal of Medical Genetics 2021;38(3):264-267
OBJECTIVE:
To delineate the origin and structure of 3 cases of small supernumerary marker chromosomes (sSMCs) through cytogenetic and molecular genetic analysis.
METHODS:
Conventional G, C and N banding were carried out to analyze the chromosomal karyotypes. Chromosomal microarray analysis (CMA) and fluorescence in situ hybridization (FISH) were used to delineate the origin and structure of the sSMCs.
RESULTS:
In case 1, chromosomal karyotype of peripheral blood sample was 47,XY,+mar. This de novo sSMC was a dual-satellited dicentric inverted duplicated marker chromosome, for which CMA yielded a normal result. It was predicted to not increase the risk of offspring. In case 2, the fetal chromosomal karyotype was 47,XY,+mar[17]/46,XY[33]. Chromosomal banding suggested that this de novo segment contained euchromatin, and the result of CMA was arr[hg19] 5p12q11.1(45 694 574-49 475 697) × 3. FISH showed the sSMC to be a fragment derived from 5p12 containing the HCN1 gene. Case 3 was found to have a fetal karyotype of 45,XY,-13[25]/46,XY,r(13)[18]/46,XY,-13,+mar[7]. Both parents had refused further examination.
CONCLUSION
Conventional chromosomal banding combined with molecular methods can delineate the origin and structure of the sSMCs, which can help with prediction of their pathogenicity and facilitate genetic counseling.
Chromosome Banding
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Chromosome Disorders
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Cytogenetics
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Humans
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In Situ Hybridization, Fluorescence
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Karyotyping
2.Genetic analysis of a case with 2q37 microdeletion syndrome.
Xiaohui LIAN ; Xiao ZHANG ; Mingyan HUANG ; Juan LIN ; Jian ZENG
Chinese Journal of Medical Genetics 2022;39(1):81-84
OBJECTIVE:
To diagnose and fine map a deletion in chromosome region 2q37.
METHODS:
G-banded chromosomal karyotyping, multiplex ligation-dependent probe amplification (MLPA), single nucleotide polymorphism array (SNP-array), and fluorescence in situ hybridization (FISH) were carried out in conjunct for the analysis.
RESULTS:
The patient was found to have karyotype of 46,XY,del(2)(q3?), MLPA revealed one copy number of both CAPN10-3 and ATG4B-7 genes from the 2q37.3 region, Both parents were found to be normal upon chromosome karyotyping and MLPA. SNP-array has found a 9.7 Mb deletion in the 2q37.1.37.3 region. FISH analysis has confirmed there is a single copy for 2q37.3.
CONCLUSION
Combination of MLPA, FISH and SNP-array have enabled accurate diagnosis for the patient, and also provided more clues for the correlation of genotype with the phenotype of the disease, and a basis for genetic counseling.
Chromosome Banding
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Chromosome Deletion
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Humans
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In Situ Hybridization, Fluorescence
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Karyotyping
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Phenotype
3.A rare case of dicentric ring chromosome and derivative ring chromosome Chimera.
Junzhen ZHU ; Xiaoping YU ; Xiaofeng QI ; Qinying CAO ; Wenshuang ZHU ; Dan YANG ; Haoyu ZHANG ; Zhanyun SONG ; Shibo WANG ; Cuixia WANG
Chinese Journal of Medical Genetics 2022;39(5):534-536
OBJECTIVE:
Utilize high-resolution chromosome analysis and microarray detection to determine the genetic etiology of infertility of a 32-year old female patient.
METHODS:
The peripheral blood of the patient was cultured for high-resolution chromosome G and C banding karyotype analysis, and then 750K SNP-Array chip detection was performed.
RESULTS:
Karyotype analysis results showed that the patient's karyotype was 45,XX,-13 [7]/46,XX,r(13) (p13q34) [185]/46,XX,dic r(13;13)(p13q34;p13q34) [14]/ 47,XX,+der(13;13;13;13) (p13q34;p13q34;p13q34; p13q34), dic r(13;13) [1]/ 46,XX [3]. The microarray results showed that the patient had a 3.3 Mb deletion in the 13q34 segment of chromosome 13, which may be related to infertility.
CONCLUSION
Infertility of the patient reported in this article may be related to the deletion of chromosome segment (13q34-qter).
Adult
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Chimera
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Chromosome Banding
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Chromosome Deletion
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Chromosome Disorders/genetics*
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Dacarbazine
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Female
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Humans
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Infertility/genetics*
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Ring Chromosomes
4.Phenotypic and genetic analysis of a child with partial trisomy 7q.
Chaojie WANG ; Dongxiao LI ; Yaodong ZHANG ; Jinghui KONG ; Rui LI ; Chao GAO ; Qing SHANG ; Huichun ZHANG
Chinese Journal of Medical Genetics 2023;40(5):604-608
OBJECTIVE:
To define the nature and origin of a chromosomal aberration in a child with unexplained growth and development retardation, and to analyze its genotype-phenotype correlation.
METHODS:
A child who had presented at the Affiliated Children's Hospital of Zhengzhou University on July 9, 2019 was selected as the study subject. Chromosomal karyotypes of the child and her parents were determined with routine G-banding analysis. Their genomic DNA was also analyzed with single nucleotide polymorphism array (SNP array).
RESULTS:
Karyotyping analysis combined with SNP array suggested that the chromosomal karyotype of the child was 46,XX,dup(7)(q34q36.3), whilst no karyotypic abnormality was found in either of her parents. SNP array has identified a de novo 20.6 Mb duplication at 7q34q36.3 [arr[hg19] 7q34q36.3(138335828_158923941)×3] in the child.
CONCLUSION
The partial trisomy 7q carried by the child was rated as a de novo pathogenic variant. SNP array can clarify the nature and origin of chromosomal aberrations. Analysis of the correlation between genotype and phenotype can facilitate the clinical diagnosis and genetic counseling.
Female
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Humans
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Trisomy/genetics*
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Phenotype
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Genotype
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Karyotyping
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Chromosome Banding
5.Clinical and genetic analysis of a patient with 10q26.3 microdeletion in conjunct with 18q22.3q23 microduplication.
Jianlong ZHUANG ; Shuhong ZENG ; Yuanbai WANG ; Yuying JIANG
Chinese Journal of Medical Genetics 2022;39(12):1415-1418
OBJECTIVE:
To explore the genetic etiology for a patient featuring intellectual disability and torticollis.
METHODS:
Peripheral blood sample was collected from the patient and subjected to G-banded karyotyping analysis and single nucleotide polymorphism array (SNP-array) assay.
RESULTS:
The patient was found to have a chromosomal karyotype of 46,XX. SNP-array revealed that she has harbored a 3.8 Mb microdeletion at 10q26.3 which has encompassed 21 OMIM genes including EBF3 and ECHS1, and a 7.3 Mb duplication at 18q22.3q23 which has encompassed 19 OMIM genes including TSHZ1 and TXNL4A. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the 10q26.3 deletion was predicted to be pathogenic, whilst the 18q22.3q23 duplication was predicted to be variation of unknown significance.
CONCLUSION
The clinical phenotype of the patient may be mainly attributed to the 10q26.3 microdeletion, and haploinsufficiency of the EBF3 gene may account for her intellectual deficiency. Above finding has provided a basis for genetic counseling for the patient.
Female
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Animals
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Genetic Testing
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Genetic Counseling
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Karyotyping
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Chromosome Banding
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Genomics
6.Clinical and laboratory features of 13 cases of myeloid neoplasms with double del (20q).
Shuxiao BAI ; Chunxiao WU ; Jun ZHANG ; Suning CHEN ; Jinlan PAN
Chinese Journal of Medical Genetics 2017;34(4):546-549
OBJECTIVETo report on clinical and laboratory features of myeloid neoplasms with double del(20q).
METHODSCytogenetic examination of bone marrow was performed on 13 cases of myeloid neophasms with double del(20q) after 24 hours of cell culture. R-banding was used to analyze the karyotypes. Interphase fluorescence in situ hybridization (FISH) was performed using dual-color probes for 20q11/20q12.
RESULTSDouble del(20q) was found to be the sole abnormality in 9 cases, double del(20q) and trisomy 9 was found in 1 case, trisomy del(20q) was found in 1 case, and sole del(20q) clone and double del(20q) clone were found to coexist in 2 cases. In 10 cases, interphase FISH showed one green and one red signal in cells with del(20q), which indicated deletion of both 20q11 and 20q12. Immunophenotyping of the leukemia cells showed positiveness for CD13 and/or CD33, CD117 in all 9 cases. Among these, co-expression of CD34 and/or HLA-DR was found in 6 cases, and coexpression of CD3 and CD7 was found in 1 case. Of the 13 cases, there were one AML-M6, nine MDS, one pure amegalokaryocye aplastic thrombocytopenia, one with normal morphology of bone marrow, and one undetermined due to dilution of the bone marrow by blood. Cytopenia were found in all cases. 9 of 13 cases died, and 4 survived with a median survival of 9 months.
CONCLUSIONDouble del(20q) is a rare but recurrent chromosomal abnormality derived from del(20q). It has unique clinical and laboratory features, and the prognosis is poor.
Aged ; Chromosome Banding ; methods ; Chromosome Deletion ; Female ; Humans ; Male ; Middle Aged ; Myelodysplastic Syndromes ; genetics ; Neoplasms ; genetics
8.Phenotypic and genetic analysis of a child featuring multiple malformations due to chromosome 18p deletion.
Qiong PAN ; Ping HU ; Jihua OU ; Xin JIN ; Fengting ZHANG ; Yue HU ; Longfei CHENG ; Liangrong HAN ; Ying NING
Chinese Journal of Medical Genetics 2015;32(5):695-699
OBJECTIVE To analyze a neonate with multiple malformations and to correlate its genotype with phenotype. METHODS The karotypes of the child and her parents were subjected to G-banding chromosome analysis, and array comparative genomic hybridization (array-CGH) was used for fine mapping of the aberrant region. RESULTS The karyotype of the child was ascertained as 46,XX,del(18)(p11.2). Array CGH has identified a 9.8 Mb deletion at 18p11.32-p11.22. The patient has presented features such as holoprosencephaly, choanal atresia, heart defect, and craniofacial dysmorphisms. CONCLUSION The de novo 18p deletion probably underlies the main clinical manifestations of the child.
Abnormalities, Multiple
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genetics
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Chromosome Banding
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Chromosome Deletion
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Chromosomes, Human, Pair 18
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Female
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Humans
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Infant, Newborn
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Phenotype
9.Prenatal diagnosis and genetic analysis of a rare case with 8p deletion and duplication.
Xinying CHEN ; Hanbin PAN ; Shuhong ZENG ; Yuying JIANG ; Yuanbai WANG ; Jianlong ZHUANG
Chinese Journal of Medical Genetics 2023;40(1):96-100
OBJECTIVE:
To explore the genetic etiology for a child featuring mental retardation, language delay and autism.
METHODS:
G-banding chromosomal karyotyping and single nucleotide polymorphism array (SNP-array) were carried out for the child and her parents.
RESULTS:
The child was found to have a 46,XX,dup(8p?) karyotype, for which both of her parents were normal. SNP-array revealed that the child has harbored a 6.8 Mb deletion in 8p23.3p23.1 and a 21.8 Mb duplication in 8p23.1p12, both of which were verified as de novo pathogenic copy number variants.
CONCLUSION
The clinical features of the child may be attributed to the 8p deletion and duplication. SNP-array can facilitate genetic diagnosis for children featuring mental retardation in conjunct with other developmental anomalies.
Humans
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Child
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Pregnancy
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Female
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Intellectual Disability/genetics*
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Prenatal Diagnosis
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Karyotyping
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Chromosome Banding
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Chromosome Deletion
10.Clinical genetic analysis of an infant with 1q21.3-qter duplication and Xpter-p11 deletion caused by maternal balanced chromosomal translocation.
Lin LIN ; Chen ZHAO ; Yanchun LV ; Xiangyu ZHAO ; Lin LI
Chinese Journal of Medical Genetics 2022;39(5):514-517
OBJECTIVE:
To investigate the clinical phenotype and genetic diagnosis of an infant featuring multiple hair and hyperbilirubinemia.
METHODS:
Conventional G-banding analysis, chromosomal microarray analysis (CMA) and fluorescence in situ hybridization (FISH) for the patient were conducted, G-banding analyses of peripheral blood for the infant's parents were also performed.
RESULTS:
We investigated an infant who carries a unbalanced, maternally inherited karyotype 46, X, der (X) t (X;1) (p11.22; q21.3) in which CMA and FISH analyses disclosed a 1q21.3q44 duplication of 93.03 Mb and Xp22.33p11.22 deletion of 54.53 Mb.
CONCLUSION
The phenotypes of this infant can probably be attributed to the 1q21.3q44 duplication and Xp22.33p11.22 deletion, which were maternally inherited.
Chromosome Banding
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Chromosome Deletion
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Genetic Testing
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Humans
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In Situ Hybridization, Fluorescence
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Karyotyping
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Translocation, Genetic