OBJECTIVE: To explore the coincidence rate of G-banding karyotype analysis and fluorescence in situ hybridization (FISH) for the diagnosis of children with sex chromosome mosaicisms. METHODS: A retrospective analysis was carried out for 157 children with suspected sex chromosome abnormalities who had presented at Shenzhen Children's Hospital from April 2021 to May 2022. Interphase sex chromosome FISH and G-banding karyotyping results were collected. The coincidence rate of the two methods in children with sex chromosome mosaicisms was compared. RESULTS: The detection rates of G-banding karyotype analysis and FISH were 26.1% (41/157) and 22.9% (36/157) , respectively (P > 0.05). The results of G-banding karyotype analysis showed that 141 cases (89.8%) were in the sex chromosome homogeneity group, of which only 5 cases (3.5%) were inconsistent with the results of FISH. There were 16 cases (10.2%) in the sex chromosome mosaicism group, of which 11 cases (68.8%) were inconsistent with the results of FISH. There was a statistical difference between the two groups in the coincidence rate of the results of the two methods (P < 0.05). CONCLUSION No significant difference was found between G-banding karyotype analysis and FISH in the detection rate of chromosome abnormalities. The coincidence rate in the mosaicism group was lower than that in the homogeneity group, and the difference was statistically significant. The two methods should be combined for clinical diagnosis.
Humans ; Mosaicism ; In Situ Hybridization, Fluorescence/methods* ; Retrospective Studies ; Karyotyping ; Chromosome Aberrations ; Sex Chromosome Aberrations ; Karyotype ; Chromosome Banding ; Sex Chromosomes

OBJECTIVETo explore the clinical and genetic characteristics of a case with Pallister-Killian syndrome (PKS).

METHODSChromosomal karyotype of umbilical cord blood sample derived from a 36-year-old pregnant woman was analyzed by G-banding analysis. After birth, the child was further analyzed with single nucleotide polymorphism microarray (SNP array) and fluorescence in situ hybridization (FISH) using 12pter/12qter probes.

RESULTSG-banding analysis showed that the fetus has a karyotype of 46,XY [77]/47,XY,+mar [23]. After birth, Affymetrix CytoScan 750K array analysis showed a segmental tetrasomy of arr [hg19] 12p13.33p11.1(173 786 - 34 835 641)×4 and a 34.6 Mb repeat at 12p13.33p11.1 with in the neonate. FISH analysis confirmed that 39% of cells harbored the 12p tetrasomy.

CONCLUSIONCombined clinical examination, G-banded chromosomal karyotyping, FISH and microarray analysis can delineate the origin and fragments of small supernumerary marker chromosomes and diagnose PKS with precision.

Adult ; Chromosome Banding ; Chromosome Disorders ; diagnosis ; Chromosomes, Human, Pair 12 ; Female ; Humans ; In Situ Hybridization, Fluorescence ; methods ; Karyotyping ; Oligonucleotide Array Sequence Analysis ; Polymorphism, Single Nucleotide ; Pregnancy ; Prenatal Diagnosis ; methods

OBJECTIVETo explore the pathogenesis of a child with growth retardation, liver damage and congenital heart disease.

METHODSG-banded chromosomal karyotyping, high-throughput next-generation sequencing (HT-NGS)and fluorescence in situ hybridization(FISH) were used to characterize the structural chromosomal aberration.

RESULTSThe child was found to have a karyotype of 46, XX, t(1;2) (q25;q21), t(7;20) (q21;p13). HT-NGS has detected a microdeletion at 2q21.3 and 7q21.11, respectively, which were verified by FISH.

CONCLUSIONCombined cytogenetic and molecular analysis can detect chromosome micrdeletions more precisely. The abnormalities of the child may be attributed to heterozygous deletion of ZEB2, ABCB4 and SEMA3A genes.

Chromosome Aberrations ; Chromosome Banding ; methods ; Female ; Heart Defects, Congenital ; genetics ; Humans ; Infant ; Intellectual Disability ; genetics ; Karyotyping ; methods ; Liver Diseases ; genetics

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

OBJECTIVETo explore the genetic cause of a female patient with severe mental retardation and a history of adverse pregnancy.

METHODSThe patient was subjected to G-banded chromosome analysis and single nucleotide polymorphism array (SNP-array) assaying. The correlation between genomic variations and the phenotype was explored.

RESULTSThe patient was found to have a complex chromosome rearrangement involving 5 chromosomes. The karyotypes of her parents were both normal. SNP-array assay has identified a 1.6 Mb microdeletion at chromosome 15q21.3 which involved 15 RefSeq genes and a 0.5 Mb microdeletion at 5q21.1 which involved one RefSeq gene.

CONCLUSIONThe microdeletions, which involved TCF12, ADMA10 and AQP9 genes, probably underlie the mental retardation shown by the patient.

Adult ; Chromosome Banding ; methods ; Chromosome Deletion ; Chromosomes ; genetics ; Female ; Genetic Testing ; methods ; Humans ; Intellectual Disability ; genetics ; Karyotype

OBJECTIVETo explore the implications of copy number variations (CNVs) for congenital heart diseases (CHD) in fetuses.

METHODSG-banding karyotype analysis and next-generation sequencing (NGS) technology were performed on cord blood samples derived from 36 fetuses with CHD. Pathological implication of the CNVs was explored through comparison against the International Genomic Polymorphism Database (http://www.ebi.ac.uk/dgva/), Phenotype Database (http://decipher.sanger.ac.uk/), and the Human Genome Database at UCSC (http://genome.ucsc.edu/cgi-bin/hgGateway).

RESULTSG-banding karyotype analysis has identified 7 chromosomal abnormalities. For the remaining 28 cases, NGS has identified 4 microdeletions and microduplications, which involved chromosomes 2, 13, 14, 16 and 22. The largest involved a 6.8 Mb microdeletion, while the smallest involved a 280 kb microduplication. The chromosomal breakpoints in 1 case were delineated. One case of Noonan syndrome and one case of 22q11.2 deletion were diagnosed.

CONCLUSIONNGS can accurately determine the origins of derivative chromosomes and facilitate identification of pathogenic CNVs/genes. It can serve as a useful complement for conventional G-banding and reduce the recurrence risk.

Chromosome Aberrations ; Chromosome Banding ; methods ; DNA Copy Number Variations ; genetics ; Fetus ; abnormalities ; Heart Defects, Congenital ; genetics ; High-Throughput Nucleotide Sequencing ; methods ; Humans ; Karyotyping ; methods

OBJECTIVETo explore the correlation between 13q33-q34 microdeletion and clinical phenotype.

METHODSRoutine chromosomal banding was performed to analyze the karyotype, while array-based comparative genomic hybridization (aCGH array) and single nucleotide polymorphism array(SNP array) were employed to investigate the genome copy number variations.

RESULTSThe karyotype of patient 1 was 46, XY, 9qh+,13qs. Patient 2 showed 46, XX, der (13). Patient 3 showed 46, XX, r(13) (p11.2q32) [43]/45, XX, 13[4]/46, XX, r(13;13) [2]/47, XX, 2r(13;13) [1]. Patient 4 did not undergo chromosome karyotyping analysis. Array analysis showed that four patients have different microdeletions in 13q33-34 region and had common features of 13q33-q34deletion including intellectual disability, facial dysmorphism, microcephaly, hypotonia, low birth weight and genital abnormality.

CONCLUSIONThe severity of phenotypes showed no correlation with the size of deletion in 13q33-q34. The lower percentage of patients with congenital heart disease suggested a complex pathogenesis of such disease. EFNB2, LIG4 and SOX1 in 13q33-34 region are promising candidates for mental retardation. LIG4 was also a likely candidate for microcephaly.

Child, Preschool ; Chromosome Banding ; methods ; Chromosome Deletion ; Chromosomes, Human, Pair 13 ; genetics ; Female ; Genetic Testing ; methods ; Humans ; Infant ; Intellectual Disability ; genetics ; Male

OBJECTIVETo explore the genetic cause of a female case with intellectual development disorder.

METHODSG banding karyotyping was performed for the patient. Following DNA extraction, the coding sequence of SRY gene was amplified with PCR and subjected to Sanger sequencing. qPCR was used to detect the copy numbers of the SRY gene.

RESULTSThe karyotype of the patient was 47,XXY. PCR and qPCR analyses of the SRY gene showed a large deletion with null copy number.

CONCLUSIONThe female phenotype of the patient is probably due to deletion of the SRY gene on the Y chromosome. This is the first report of 47,XXY female case with deletion of the SRY gene in China.

Base Sequence ; Chromosome Banding ; Chromosomes, Human, Y ; genetics ; Female ; Genes, sry ; genetics ; Humans ; Intellectual Disability ; genetics ; Karyotype ; Karyotyping ; Klinefelter Syndrome ; genetics ; Male ; Polymerase Chain Reaction ; Review Literature as Topic ; Sequence Analysis, DNA ; methods ; Sequence Deletion ; Sequence Homology, Nucleic Acid

OBJECTIVETo analyze three cases with partial 21q trisomy, and correlate their genotypes with phenotypes.

METHODSG-banding chromosomal analysis and single nucleotide polymorphism (SNP array) were performed for the three cases and their parents.

RESULTSSNP array has detected partial 21q trisomy in three cases and one mother, with variable size and location of the duplications. Case 1 harbored a 12.35 Mb duplication at 21q22.11q22.3, which spanned the Down syndrome critical region. Case 2 harbored a 35.32 Mb duplication at 9p24.3p13.3 and a 14.42 Mb duplication at 21q11.2q21.3, with the former spanning the partial 9p trisomy syndrome critical region excluding the Down syndrome critical region, and was inherited from his mother. Case 3 harbored a 4.17 Mb tetraploidy at 21q11.2q21.1 in the form of mosaicism, which spared the Down syndrome critical region. His mother carried a 4.17 Mb triploidy at 21q11.2q21.1, which was also a mosaicism.

CONCLUSIONPartial 21q trisomy may occur in various forms and its clinical phenotypes are heterogeneous. Combined use of genetic techniques, particularly SNP array, is crucial for diagnosing partial 21q trisomy and delineating its genotype-phenotype correlation.

Child, Preschool ; Chromosome Banding ; Down Syndrome ; genetics ; Female ; Genotype ; Humans ; Infant ; Infant, Newborn ; Male ; Microarray Analysis ; methods ; Polymorphism, Single Nucleotide

OBJECTIVETo carry out chromosomal microarray analysis (CMA) on four fetuses with abnormal karyotypes.

METHODSAmniotic fluid samples were obtained and subjected to routine G-banded karyotyping analysis. CMA was applied for cultured amniocytes to determine alterations of gene dosage and chromosomal breakpoints.

RESULTSAbnormal karyotypes were found in the parents of 3 fetuses. Parental karyotypes of the remaining fetus were normal. Imbalance chromosome rearrangements were revealed by CMA in all 4 cases.

CONCLUSIONCMA is an effective tool for the evaluation of clinical significance and delineation of the breakpoints involved in complex chromosomal rearrangements.

Abnormal Karyotype ; Adult ; Chromosome Banding ; Female ; Humans ; Karyotyping ; Microarray Analysis ; methods ; Pregnancy ; Prenatal Diagnosis