Theoretically, microduplication of chromosomal region 22q11.2, which is rich in segmental duplications, should be as frequent as microdeletions of the same region. Preliminary analysis on the rarity of reports for 22q11.2 microduplication in the literature has suggested that, for the discovery of 22q11.2 microduplication, there has been a lack of sensitivity for routine diagnostic techniques such as karyotyping, PCR and FISH. On the other hand, the diverse anomalies and extremely variable phenotypes of carriers also implied great difficulties one has to face upon clinical consultation. Genetics as well as clinical problems in connection with 22q11.2 microduplication has vividly illustrated the great challenge for the interpretation of genotype-phenotype correlation, and thereby posed yet another gray zone for clinical genetics research.
Chromosome Deletion ; Chromosomes, Human, Pair 22 ; genetics ; Gene Duplication ; Genetics, Medical ; Humans ; Phenotype

OBJECTIVE: To explore the molecular mechanism of a girl with developmental delay and intellectual disability. METHODS: Chromosomal karotypes of the child and her parents were analyzed with routine G-banding method. Their genomic DNA was also analyzed with array comparative genomic hybridization (aCGH) for chromosomal duplications/deletions. RESULTS: No karyotypic abnormality was detected in the child and her parents, while aCGH has identified a de novo 3.37 Mb deletion at 17p11.2 in the child. CONCLUSION The child was diagnosed with Smith-Magenis syndrome, for which RAI1 may be the causative gene.
Child ; Chromosome Deletion ; Chromosome Duplication ; Chromosomes, Human, Pair 17 ; genetics ; Comparative Genomic Hybridization ; Female ; Humans ; Karyotyping ; Smith-Magenis Syndrome ; genetics

BACKGROUNDLung cancer has become the leading cause of death in many regions. Carcinogenesis is caused by the stepwise accumulation of genetic and chromosomal changes. The aim of this study was to investigate the chromosome and gene alterations in the human lung adenocarcinoma cell line OM.

METHODSWe used Giemsa banding and multiplex fluorescence in situ hybridization focusing on the human lung adenocarcinoma cell line OM to analyze its chromosome alterations. In addition, the gains and losses in the specific chromosome regions were identified by comparative genomic hybridization (CGH) and the amplifications of cancer-related genes were also detected by polymerase chain reaction (PCR).

RESULTSWe identified a large number of chromosomal numerical alterations on all chromosomes except chromosome X and 19. Chromosome 10 is the most frequently involved in translocations with six different interchromosomal translocations. CGH revealed the gains on chromosome regions of 3q25.3-28, 5p13, 12q22-23.24, and the losses on 3p25-26, 6p25, 6q26-27, 7q34-36, 8p22-23, 9p21-24, 10q25-26.3, 12p13.31-13.33 and 17p13.1-13.3. And PCR showed the amplification of genes: Membrane metalloendopeptidase (MME), sucrase-isomaltase (SI), butyrylcholinesterase (BCHE), and kininogen (KNG).

CONCLUSIONSThe lung adenocarcinoma cell line OM exhibited multiple complex karyotypes, and chromosome 10 was frequently involved in chromosomal translocation, which may play key roles in tumorigenesis. We speculated that the oncogenes may be located at 3q25.3-28, 5p13, 12q22-23.24, while tumor suppressor genes may exist in 3p25-26, 6p25, 6q26-27, 7q34-36, 8p22-23, 9p21-24, 10q25-26.3, 12p13.31-13.33, and 17p13.1-13.3. Moreover, at least four genes (MME, SI, BCHE, and KNG) may be involved in the human lung adenocarcinoma cell line OM.

Adenocarcinoma ; genetics ; Cell Line, Tumor ; Chromosome Aberrations ; Chromosome Banding ; Chromosome Duplication ; Comparative Genomic Hybridization ; Humans ; In Situ Hybridization, Fluorescence ; Karyotype ; Lung Neoplasms ; genetics ; Polymerase Chain Reaction ; Translocation, Genetic

OBJECTIVE: To explore the origin and mechanism of small supernumerary marker chromosomes (sSMC) in three fetuses. METHODS: The three fetuses were predicted to have carried chromosomal abnormalities by non-invasive prenatal testing (NIPT). G-banding chromosomal karyotyping analysis were carried out on amniotic fluid samples of the fetuses and peripheral blood samples from their parents. Single nucleotide polymorphism array (SNP-array) was used to determine the origin, size and genetic effect of sSMCs. RESULTS: In fetus 1, SNP array has detected two microduplications respectively at 4p16.3p15.2 (24.7 Mb) and 18p11.32q11.2 (20.5 Mb) which, as verified by fluorescence in situ hybridization (FISH), have derived from a balanced 46,XY,t(4;18)(p15.2q11.2) translocation carried by its father. Fetus 2 has carried a de novo microduplication of 15q11.2-q13.3 (9.7 Mb). The sequence of SMC in fetus 3 has derived from 21q11.2-q21.1 (8.3 Mb), which was inherited from its mother. CONCLUSION Both NIPT and SNP-array are highly accurate for the detection of sSMC. SNP-array can delineate the origin and size of abnormal chromosomes, which in turn can help with clarification of sSMC-related genotype-phenotype correlation and facilitate prenatal diagnosis and genetic counseling for the family.
Chromosome Duplication/genetics* ; Female ; Fetus ; Humans ; In Situ Hybridization, Fluorescence ; Male ; Polymorphism, Single Nucleotide ; Pregnancy ; Prenatal Diagnosis ; Translocation, Genetic/genetics*

Pericentric inversion of chromosome 4 can give rise to 2 alternate recombinant (rec) chromosomesby duplication or deletion of 4p. The deletion of distal 4p manifests as Wolf-Hirschhorn syndrome (WHS). Here, we report the molecular cytogenetic findings and clinical manifestations observed in an infant with 46,XX,rec(4)dup(4q)inv(4)(p16q31.3)pat. The infant was delivered by Cesarean section at the 33rd week of gestation because pleural effusion and polyhydramnios were detected on ultrasonography. At birth, the infant showed no malformation or dysfunction, except for a preauricular skin tag. Array comparative genomic hybridization analysis of neonatal peripheral blood samples showed a gain of 38 Mb on 4q31.3-qter and a loss of 3 Mb on 4p16.3, and these results were consistent with WHS. At the last follow-up at 8 months of age (corrected age, 6 months), the infant had not achieved complete head control.
*Chromosome Deletion ; *Chromosome Duplication ; *Chromosome Inversion ; *Chromosomes, Human, Pair 4 ; Comparative Genomic Hybridization ; Female ; Gestational Age ; Humans ; Infant ; Pleural Effusion/ultrasonography ; Polyhydramnios/ultrasonography ; Pregnancy ; Wolf-Hirschhorn Syndrome/*genetics

OBJECTIVETo determine the value of spectral karyotyping (SKY) to identify the complex chromosome aberration.

METHODSFour cases were selected that can not be identified by standard cytogenetic techniques. The chromosome specimens were detected by the routine SKY method, and the results were analyzed by the SKY View software.

RESULTSBy using SKY a case of complex chromosome rearrangements and two cases of chromosome duplication were identified. However it could not identify the chromosome inversion and the breakpoint of chromosome aberration.

CONCLUSIONSKY may be a valuable tool in identification of complex chromosome translocation, rearrangement, minute aberration and unknown derivative chromosomes. Though SKY can not replace the standard cytogenetic techniques, but it will be the benefit supplementary.

Adult ; Chromosome Aberrations ; Chromosome Banding ; Chromosome Disorders ; diagnosis ; genetics ; Female ; Gene Duplication ; Humans ; In Situ Hybridization, Fluorescence ; Infant ; Male ; Reproducibility of Results ; Sensitivity and Specificity ; Spectral Karyotyping ; methods ; Translocation, Genetic

OBJECTIVETo investigate the relationship between subtelomeric rearrangements and idiopathic mental retardation (MR).

METHODSThirty unrelated patients were recruited using strict selection criteria. Patients were screened by multiplex ligation-dependent probe amplification (MLPA) for subtelomeric imbalance.

RESULTSFive subtelomeric deletions/duplications were identified. They were: 4p deletion, 21p duplication, 10p duplication combined with 4p deletion, 15p duplication, and 9p deletion combined with 3p duplication. These subtelomeric rearrangements were previously unidentified by conventional technique.

CONCLUSIONChildren with unexplained mental retardation are related with subtelomeric rearrangements. MLPA is a rapid and an effective technique for detecting genetic abnormalities in patients with idiopathic MR.

Child ; Chromosome Aberrations ; Female ; Gene Deletion ; Gene Duplication ; Humans ; Intellectual Disability ; diagnosis ; genetics ; Ligase Chain Reaction ; methods ; Male

OBJECTIVE: To explore the genetic basis for a Chinese pedigree with 6q26q27 microduplication and 15q26.3 microdeletion. METHODS: A fetus with a 6q26q27 microduplication and a 15q26.3 microdeletion diagnosed at the First Affiliated Hospital of Wenzhou Medical University in January 2021 and members of its pedigree were selected as the study subject. Clinical data of the fetus was collected. The fetus and its parents were analyzed by G-banding karyotyping and chromosomal microarray analysis (CMA), and its maternal grandparents were also subjected to G-banding karyotype analysis. RESULTS: Prenatal ultrasound had indicated intrauterine growth retardation of the fetus, though no karyotypic abnormality was found with the amniotic fluid sample and blood samples from its pedigree members. CMA revealed that the fetus has carried a 6.6 Mb microduplication in 6q26q27 and a 1.9 Mb microdeletion in 15q26.3, and his mother also carried a 6.49 duplication and a 1.867 deletion in the same region. No anomaly was found with its father. CONCLUSION The 6q26q27 microduplication and 15q26.3 microdeletion probably underlay the intrauterine growth retardation in this fetus.
Female ; Humans ; Pregnancy ; East Asian People ; Fetal Growth Retardation/genetics* ; Karyotype ; Pedigree ; Prenatal Diagnosis ; Sequence Deletion ; Chromosome Duplication

OBJECTIVETo investigate the association between genotype and phenotype of microdeletion and microduplication syndromes (MMSs) and the pathogenesis of pathogenic copy number variations (CNVs).

METHODSA total of 50 children with MMSs diagnosed by chromosomal microarray analysis (CMA) from June 2013 to September 2015 were enrolled, and the clinical manifestations and features of pathogenic CNVs were analyzed.

RESULTSThe main clinical manifestations of children with MMSs included mental retardation, developmental delay, short stature, and unusual facies, with the presence of abnormalities in multiple systems. There were 54 pathogenic CNVs in total, consisting of 36 microdeletion segments and 18 microduplication segments, with sizes ranging from 28 kb to 48.5 Mb (mean 13.86 Mb). Pathogenic CNVs often occurred in chromosomes X, 15, and 1.

CONCLUSIONSThe clinical manifestations of MMSs are not specific, and a genotype-first approach can be used for diagnosis. Mode of inheritance, type of recombination (deletion or duplication), size of segment, and functional genes included helps with the interpretation of CNVs of de novo mutations, and in-depth research on rare pathogenesis may become breakthrough points for the identification of new MMSs.

Adolescent ; Child ; Child, Preschool ; Chromosome Deletion ; Chromosome Duplication ; DNA Copy Number Variations ; Developmental Disabilities ; genetics ; Female ; Humans ; Infant ; Intellectual Disability ; genetics ; Male ; Phenotype ; Retrospective Studies ; Syndrome

OBJECTIVETo define the origin and the precise location of the aberrant fragments on the short arm of the chromosome 8 in a mentally retarded boy, and to understand the mechanism, the characteristic clinical features and the recurrent risk associated with this abnormality.

METHODSHigh-resolution chromosomal banding was performed to analyze the karyotype of the patient and his parents, array comparative genomic hybridization (array-CGH) was employed to investigate the precise location of the aberrant fragments, and quantitative real-time PCR was used to confirm the results.

RESULTSThe rearranged chromosome 8 in the patient was inverted and duplicated for region 8p11.2-p23.1, and deleted for region 8p23.1-pter. In between, a 5.70 Mb single copy region was present, which was delimited by the two olfactory receptor (OR) gene clusters.

CONCLUSIONThis is a case of classic inv dup del(8p) syndrome, which is characterized by severe mental retardation, brain malformation and specific facial dysmorphism, and is induced by non-allelic homologous recombination (NAHR) between the OR genes on 8p23.1. Prenatal diagnosis should be performed to monitor the recurrent risk of inv dup del(8p), as well as the other three harmful consequences resulted from the same NAHR mechanism. To the best of our knowledge, this is the first case of inverted duplicated 8p syndrome identified in Mainland China.

Abnormalities, Multiple ; genetics ; China ; Chromosome Aberrations ; classification ; Chromosome Banding ; methods ; Chromosome Deletion ; Chromosome Inversion ; Chromosome Mapping ; Chromosomes, Human, Pair 8 ; Cytogenetic Analysis ; methods ; Cytogenetics ; methods ; Gene Duplication ; Humans ; In Situ Hybridization, Fluorescence ; Infant ; Karyotyping ; methods ; Male ; Multigene Family ; Syndrome