After the promulgation of the first edition of expert consensus on the application of chromosomal microarray analysis (CMA) technology in prenatal diagnosis in 2014, after 8 years of clinical and technical development, CMA technology has become a first-line diagnosis technology for fetal chromosome copy number deletion or duplication abnormalities, and is widely used in the field of prenatal diagnosis in China. However, with the development of the industry and the accumulation of experience in case diagnosis, the application of CMA technology in many important aspects of prenatal diagnosis, such as clinical diagnosis testimony, data analysis and genetic counseling before and after testing, needs to be further standardized and improved, so as to make the application of CMA technology more in line with clinical needs. The revision of the guideline was led by the National Prenatal Diagnostic Technical Expert Group, and several prenatal diagnostic institutions such as Peking Union Medical College Hospital were commissioned to write, discuss and revise the first draft, which was discussed and reviewed by all the experts of the National Prenatal Diagnostic Technical Expert Group, and was finally formed after extensive review and revision. This guideline is aimed at the important aspects of the application of CMA technology in prenatal diagnosis and clinical diagnosis, from the clinical application of evidence, test quality control, data analysis and interpretation, diagnosis report writing, genetic counseling before and after testing and other work specifications are elaborated and introduced in detail. It fully reflects the integrated experience, professional thinking and guidance of the current Chinese expert team on the prenatal diagnosis application of CMA technology. The compilation of the guideline for the application of CMA technology in prenatal diagnosis will strive to promote the standardization and advancement of prenatal diagnosis of fetal chromosome diseases in China.
Female ; Humans ; Pregnancy ; Asian People ; Chromosome Aberrations ; Chromosome Deletion ; Chromosome Duplication/genetics* ; DNA Copy Number Variations/genetics* ; Fetal Diseases/genetics* ; Genetic Counseling ; Microarray Analysis ; Prenatal Care ; Prenatal Diagnosis ; Practice Guidelines as Topic

OBJECTIVE: To carry out genetic analysis for a Chinese pedigree affected with intellectual disability and overgrowth due to a supernumerary marker chromosome (sSMC). METHODS: A pedigree which had presented at Jiaxing Maternity and Child Health Care Hospital on August 31, 2021 was selected as the study subject, for which chromosomal karyotyping, single nucleotide polymorphism-based microarray (SNP-array), and fluorescence in situ hybridization (FISH) were carried out in combination. RESULTS: SNP-array analysis showed that the proband and his sister had both harbored a 16.1 Mb duplication which encompassed the critical region of 15q26 overgrowth syndrome. FISH confirmed that the proband was 47,XX,+neo(15)(qter→q25.3:)mat, her mother was 47,XX,del(15)(q25.3:),+neo(15)(qter→q25.3:), whilst her father was normal. CONCLUSION Application of multiple genetic techniques has facilitated delineation of the origin of sSMC and reliable genetic counseling for this pedigree.
Female ; Humans ; Chromosomes ; East Asian People ; In Situ Hybridization, Fluorescence ; Karyotyping ; Pedigree ; Polymorphism, Single Nucleotide ; Intellectual Disability/genetics* ; Chromosome Duplication/genetics* ; Male

Humans ; Chromosome Deletion ; Chromosome Duplication

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

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*

OBJECTIVE: To explore the genetic basis for an infant with multiple malformations including congenital heart disease and cleft palate. METHODS: The child and his parents were subjected to conventional chromosomal karyotyping and low-coverage massively parallel copy number variation sequencing (CNV-seq) analysis. RESULTS: The infant was found to have a 46,X,add(Y)(q11.23) karyotype, and his CNV-seq result was seq [hg19] 22q12.1q13.3 (29 520 001-51 180 000)× 3. His parents were found to be normal by both methods. CONCLUSION The additional chromosomal material found on Yq, verified as duplication of 22q12.1-q13.3, may account for the abnormal phenotype in this infant. CNV-seq has provided a useful complement for the diagnosis and more accurate information for genetic counseling.
Abnormalities, Multiple ; genetics ; Child ; Chromosome Duplication ; Chromosomes, Human, Pair 22 ; genetics ; Cleft Palate ; genetics ; DNA Copy Number Variations ; Genetic Testing ; Heart Defects, Congenital ; genetics ; Humans ; Infant ; Karyotyping

OBJECTIVE: To explore the genetic basis for a Chinese pedigree affected with split hand/foot malformation (SHFM). METHODS: Genomic DNA of the proband and other affected members was extracted from peripheral blood samples. Chromosomal microarray analysis was employed to detect genome-wide copy number variations (CNVs). RESULTS: A 400 kb microduplication was identified in the 10q24.31-q24.32 region among all affected individuals. The microduplication has involved four genes, namely LBX1, BTRC, POLL and DPCD, in addition with part of FBXW4 gene. CONCLUSION The 10q24.31-q24.32 microduplication has segregated with the disease phenotype in this pedigree and probably underlay the SHFM malformation in the patients.
Asian Continental Ancestry Group ; Chromosome Duplication ; Chromosomes, Human, Pair 10 ; genetics ; DNA Copy Number Variations ; Foot Deformities, Congenital ; genetics ; Genetic Testing ; Hand Deformities, Congenital ; genetics ; Humans ; Limb Deformities, Congenital ; genetics ; Pedigree

OBJECTIVE: To investigate the relationship between 22q11.2 duplication and clinical phenotype. METHODS: Eight fetuses with 22q11.2 duplication syndrome diagnosed by chromosome microarray analysis (CMA) through amniocentesis from February 2015 to March 2017 were enrolled in the study. The prenatal diagnostic indications, fetal ultrasound, chromosome karyotype, peripheral blood CMA results of parents, pregnancy outcomes and follow-up of postnatal growth and development were retrospectively analyzed. RESULTS: Prenatal serological screening indicated 6 cases with high risk of trisomy 21, 1 case with nuchal fold (NF) thickening and 1 case of maternal chromosomal balanced translocation. Fetal ultrasonography showed 1 case of NF thickening, 1 case of fetal cerebral ventriculomegaly and 6 cases with normal ultrasound. CMA demonstrated that the size of duplication was between 651 kb and 3.26 Mb, and 22q11.2 duplication. Parents' CMA results revealed that 6 cases inherited from one of the parents with normal phenotype, and the parents of 2 cases refused the CMA test. Two couples chose induced labor; 6 cases of continued pregnancy had normal phenotypes at birth. All 6 cases were followed up with longest of 3.5 years. The growth and psychological development were normal in 5 cases, and one case was growth retardation. CONCLUSIONS There were no specific clinical phenotypes in 22q11.2 duplication syndrome, and most of them were inherited from one parent who has normal phenotype.
Abnormalities, Multiple ; diagnosis ; genetics ; Chromosome Duplication ; genetics ; Chromosomes, Human, Pair 22 ; genetics ; DiGeorge Syndrome ; diagnosis ; genetics ; Female ; Humans ; Male ; Pregnancy ; Pregnancy Outcome ; Prenatal Diagnosis ; Retrospective Studies

OBJECTIVE: To explore the nature and origin of chromosomal copy number variants (CNVs) in a pedigree affected with mental retardation. METHODS: Genomic CNVs of the proband were analyzed by next generation sequencing (NGS). Chromosomal karyotypes of the proband and his relatives were analyzed with high-resolution karyotyping and fluorescence in situ hybridization (FISH). RESULTS: Clinical phenotypes of the proband and other patients from the pedigree included mental retardation and mild dysmorphism. The results of NGS revealed that the proband carried a 16.24 Mb microduplication at 4p16.3-15.32 and a 2.2 Mb microdeletion at 8p23.3-23.2. Other patients of the pedigree harbored the same variants, while those without the phenotypes did not harbor the variants. The results of high-resolution karyotyping and FISH revealed that the mother of the proband carried a reciprocal translocation between 4p and 8p, and her karyotype was 46,XX,t(4;8)(p16;p23). No karyotypic abnormality was detected in his father. CONCLUSION The abnormal phenotypes of this pedigree may be attributed to 4p microduplication in conjunct with 8p microdeletion derived from a maternal balanced translocation between 4p and 8p.
Chromosome Aberrations ; Chromosome Duplication ; Chromosomes, Human, Pair 4 ; Chromosomes, Human, Pair 8 ; Female ; Genetic Testing ; Humans ; In Situ Hybridization, Fluorescence ; Intellectual Disability ; genetics ; Karyotyping ; Pedigree ; 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