OBJECTIVE: To provide prenatal diagnosis, pedigree analysis and genetic counseling for a pregnant woman who had given birth to a child featuring global developmental delay. METHODS: A pregnant woman who underwent prenatal diagnosis at the Affiliated Hospital of Southwest Medical University in August 2021 was selected as the study subject. Peripheral blood samples were collected from the woman, her husband and child, in addition with amniotic fluid sample during mid-pregnancy. Genetic variants were detected by G-banded karyotyping analysis and copy number variation sequencing (CNV-seq). Pathogenicity of the variant was predicted based on the guidelines from the American College of Medical Genetics and Genomics (ACMG). Candidate variant was traced in the pedigree to assess the recurrence risk. RESULTS: The karyotypes of the pregnant woman, her fetus, and affected child were 46,XX,ins(18)(p11.2q21q22), 46,X?,rec(18)dup(18)(q21q22)ins(18)(p11.2q21q22)mat and 46,XY,rec(18)del(18)(q21q22)ins(18)(p11.2q21q22)mat, respectively. Her husband was found to have a normal karyotype. CNV-seq has revealed a 19.73 Mb duplication at 18q21.2-q22.3 in the fetus and a 19.77 Mb deletion at 18q21.2-q22.3 in her child. The duplication and deletion fragments were identical to the insertional fragment in the pregnant woman. Based on the ACMG guidelines, the duplication and deletion fragments were both predicted to be pathogenic. CONCLUSION The intrachromosomal insertion of 18q21.2-q22.3 carried by the pregnant woman had probably given rise to the 18q21.2-q22.3 duplication and deletion in the two offspring. Above finding has provided a basis for genetic counseling for this pedigree.
Child ; Female ; Humans ; Pregnancy ; DNA Copy Number Variations ; East Asian People ; Pedigree ; Prenatal Diagnosis/methods* ; Chromosomes, Human, Pair 18/genetics* ; Male ; Fetus ; INDEL Mutation

OBJECTIVE: To explore the genetic basis for a child featuring delayed intellectual development. METHODS: The child and his parents were subjected to conventional G-banding karyotyping and single nucleotide polymorphism array (SNP-array) analysis. Suspected copy number variations (CNVs) were verified in both parents. RESULTS: No karyotypic abnormality was found with the child and his parents. SNP-array results for both parents were normal. The child was found to harbor a de novo 172 kb deletion at 18q21.2 with a physical position of 52 957 042-53 129 237. The deletion only involved one OMIM gene, namely TCF4, resulting in removal of its exons 6 to 8. CONCLUSION The SNP-array assay has facilitated with the diagnosis of this child. Deletion of 18q21.2 region probably accounts for the Pitt-Hopkins syndrome (PTHS) in this patient.
Child ; Chromosome Deletion ; Chromosomes, Human, Pair 18 ; genetics ; DNA Copy Number Variations ; Developmental Disabilities ; genetics ; Facies ; Humans ; Hyperventilation ; genetics ; Intellectual Disability ; genetics ; Phenotype ; Transcription Factor 4 ; genetics

OBJECTIVE: To explore the genetic basis for a child with developmental delay and congenital syndactyly. METHODS: G-banding chromosomal karyotyping and chromosomal microarray analysis (CMA) were performed on peripheral blood sample from the child. RESULTS: The child was ascertained as 46, XY, r(18)[52]/45,XY,?18[3]. A 18q21.32-q23 deletion was identified by CMA with a size of 19.85 Mb, which has encompassed 99 genes including CTDP1, TXNL4A, TSHZ1, PIGN, RTTN, TNFRSF11A, KDSR and CYB5A. CONCLUSION Clinical phenotype of the patient with ring chromosome 18 is associated with the size of the euchromatin loss and involved genes. As a useful complement to conventional karyotyping, CMA has provided an powerful tool for delineating complex chromosomal aberrations.
Child ; Chromosome Aberrations ; Chromosomes, Human, Pair 18 ; genetics ; Cytogenetics ; Developmental Disabilities ; genetics ; Humans ; Karyotyping ; Ring Chromosomes ; Syndactyly ; genetics

OBJECTIVE: A popular design for the investigation of such effects, including effects of parent-of-origin (imprinting), maternal genotype, and maternal-fetal genotype interactions, is to collect deoxyribonucleic acid (DNA) from affected offspring and their mothers and to compare with an appropriate control sample. We investigate the effects of estimation of maternal, imprinting and interaction effects using multimodal modeling using parents and their offspring with schizophrenia in Korean population. METHODS: We have recruited 27 probands (with schizophrenia) with their parents and siblings whenever possible. We analyzed 20 SNPs of 7 neuronal genes in chromosome 18. We used EMIM analysis program for the estimation of maternal, imprinting and interaction effects using multimodal modeling. RESULTS: Of analyzed 20 single nucleotide polymorphisms (SNPs), significant SNP (rs 2276186) was suggested in EMIM analysis for child genetics effects (p=0.0225438044) and child genetic effects allowing for maternal genetic effects (p=0.0209453210) with very stringent multiple comparison Bonferroni correction. CONCLUSION: Our results are the pilot study for epigenetic study in mental disorder and help to understanding and use of EMIM statistical genetics analysis program with many limitations including small pedigree numbers.
Child ; Chromosomes, Human, Pair 18 ; DNA ; Epigenomics ; Genetics ; Genotype ; Humans ; Linear Models ; Mental Disorders ; Mothers ; Neurons ; Parents ; Pedigree ; Pilot Projects ; Polymorphism, Single Nucleotide ; Schizophrenia ; Siblings

OBJECTIVETo explore the genotype-phenotype correlation of a child with chromosome 18q deletion syndrome.

METHODSG-banded karyotyping, single nucleotide polymorphism array (SNP array) and fluorescence in situ hybridization (FISH) were performed on the child with abnormal phenotypes. Genotype-phenotype correlation was explored following accurate mapping of the breakpoints on chromosome 18q. SNP array was also performed on the genome DNA derived from peripheral venous blood samples from both parents.

RESULTSChromosomal analysis revealed that the child has a karyotype of 46, XY, del(18) (q23). SNP array analysis detected a 9.855 Mb deletion (chr18: 68 158 880-78 014 123) at 18q22.2q23. Mapping of the breakpoints suggested that the deletion has overlapped with that of distal chromosome 18q deletion syndrome and encompassed several critical regions for this syndrome. SNP array performed on parental samples suggested that the 18q22.2q23 deletion was de novo in origin. FISH analysis of peripheral blood sample from the child confirmed the presence of 18qter deletion.

CONCLUSIONThe phenotype of this child may be attributed to the deletion of distal 18q22.2q23, which has encompassed several critical regions for the 18q deletion syndrome.

Chromosome Deletion ; Chromosome Disorders ; genetics ; Chromosomes, Human, Pair 18 ; genetics ; Genetic Association Studies ; methods ; Genotype ; Humans ; Infant ; Phenotype ; Polymorphism, Single Nucleotide ; genetics

OBJECTIVETo determine the origin of a supernumerary small marker chromosome found in a fetus using prenatal BACs-on-Beads (BoBs) and single nucleotide polymorphism array (SNP-array) assays.

METHODSThe fetal sample was subjected to chromosomal karyotyping and BoBs analysis, and the results were validated with genome-wide scanning using a SNP microarray.

RESULTSThe fetus was found to have a 47,XX,+mar karyotype. BoBs analysis indicated that there was an amplification between 18p11.32 and 18p11.21, which was verified by the SNP-array assay as a 18.3 Mb duplication occurring at 18p11.32q11.1.

CONCLUSIONThe karyotype of the fetus was determined as 47,XX,+der18(18p11.32?18q11.1::18q11.1?18p11.32). The duplication has involved important genes including SMCHD1, LPIN2 and TGIF1, which may result in severe malformations in the fetus.

Adult ; Aneuploidy ; Chromosomes, Artificial, Bacterial ; genetics ; Chromosomes, Human, Pair 18 ; genetics ; Female ; Humans ; Karyotyping ; Microarray Analysis ; methods ; Polymorphism, Single Nucleotide ; Pregnancy ; Prenatal Diagnosis ; methods

OBJECTIVETo conduct genetic testing and prenatal diagnosis for a pregnant women with growth retardation, severe mental retardation, and a history of adverse pregnancies.

METHODSG-banded chromosome analysis, fluorescence in situ hybridization (FISH), and whole genome DNA microarray were used to analyze the patient and her fetus.

RESULTSThe women was found to be a chimera containing two cell lines with 47 and 46 chromosomes, respectively. Both have involved deletion of 18q21.2q23. FISH analysis suggested that the cell line containing 47 chromosomes has harbored a chromosome marker derived from chromosome 15. The marker has contained chromosome 15p involving the SNRPN locus and part of 15q, which gave rise to a karyotype of 47,XX,del18q21.3,+ish mar D15Z1+ SNRPN+[82]/46,XX,del18q21.3[18]. Whole genome DNA microarray confirmed that a 3.044 Mb fragment from 15q11.2q12 was duplicated, which involved NIPA1, SNRPN and other 17 OMIM genes. Duplication of this region has been characterized by low mental retardation, autism, developmental delay. Meanwhile, there was a 17.992 Mb deletion at 18q21.33q23, which contained 39 OMIM genes including TNFRSF11A and PHLPP1. This fragment was characterized by mental retardation, developmental delay, short stature, and cleft palate. Whole genome microarray analysis confirmed that there was a 17.9 Mb deletion at 18q21.33q23, which has been implemented with mental retardation, general growth retardation, short stature, and cleft palate. After genetic counseling, the family decided to terminate the pregnancy at 21st week.

CONCLUSIONCombined chromosome karyotyping, FISH, and whole genome DNA microarray can determine the origin of marker chromosomes and facilitate delineation of its correlation with the clinical phenotype.

Abortion, Eugenic ; Adult ; Chromosome Aberrations ; Chromosome Banding ; Chromosomes, Human, Pair 15 ; genetics ; Chromosomes, Human, Pair 18 ; genetics ; Fatal Outcome ; Female ; Fetus ; abnormalities ; metabolism ; Growth Disorders ; embryology ; genetics ; Humans ; In Situ Hybridization, Fluorescence ; Intellectual Disability ; embryology ; genetics ; Karyotype ; Karyotyping ; Prenatal Diagnosis ; methods

OBJECTIVETo analyze the correlation between the genotype and phenotype of 18q deletion syndrome with chromosome microarray analysis (CMA).

METHODSEight cases with 18q deletion syndrome were selected, including two affected fetuses and six children patients. DNA was extracted and hybridized with Affymetrix CytoScan TM 750K arrays following the manufacturer's standard protocol. The data was analyzed with a special software package.

RESULTSCMA analysis identified pathogenic copy number variations (CNVs) on 18q in all cases, which ranged from 6.612 Mb to 22.973 Mb. NFATC1, GALR1, MBP, SALL3 and TSHZ1 are likely to be causative genes for congenital heart disease, psychological, growth retardation, and cleft palate.

CONCLUSIONCMA can precisely locate the breakpoints of 18q and facilitate definition of the genotype-phenotype correlations, which is useful for prognosis.

Child, Preschool ; Chromosome Deletion ; Chromosome Disorders ; genetics ; Chromosomes, Human, Pair 18 ; genetics ; DNA Copy Number Variations ; Female ; Humans ; Infant ; Male ; Microarray Analysis

OBJECTIVEThe effect of rs4331426 polymorphism in the Chr18q11.2 locus on pulmonary tuberculosis (PTB) risk was evaluated.

METHODSThis case-control study included 208 PTB patients and 204 healthy subjects. Genotyping of the rs4331426 variant was conducted using polymerase chain reaction restriction fragment length polymorphism.

RESULTSThe frequencies of genotypes AA, AG, and GG polymorphisms were 83.1%, 15.9%, and 1.0% in the PTB group and 84.3%, 15.2%, and 0.5% in the control group, respectively. The frequency of the minor (G) allele was 8.9% in the PTB group and 8.1% in controls. Neither genotype nor allele frequencies of the rs4331426 variant showed statistically significant differences between PTB and controls. In addition, stratification by sex showed no significant association between the rs4331426 variant and PTB risk in males or females.

CONCLUSIONIn conclusion, the results of this study do not support an association between the rs4331426 polymorphism and risk of PTB in an Iranian population.

Adult ; Aged ; Case-Control Studies ; Chromosomes, Human, Pair 18 ; genetics ; Female ; Genetic Predisposition to Disease ; Humans ; Iran ; epidemiology ; Male ; Middle Aged ; Polymorphism, Genetic ; Tuberculosis, Pulmonary ; epidemiology ; genetics

No abstract available.
Asian Continental Ancestry Group/*genetics ; Chromosome Deletion ; Chromosome Disorders/complications/*diagnosis ; Chromosomes, Human, Pair 18 ; Cyanosis/*etiology ; Female ; Heart Septal Defects, Atrial/complications/*diagnosis ; Humans ; Infant ; Karyotyping ; Republic of Korea