OBJECTIVE: To assess the value of chromosomal microarray analysis (CMA) for the diagnosis of fetuses with anomalies of the central nervous system (CNS) and summarize the outcome of the pregnancies and follow-up. METHODS: A total of 636 fetuses from June 2014 to December 2020 who were referred to the Prenatal Diagnosis Center of Nanjing Drum Tower Hospital due to abnormal CNS prompted by ultrasound were selected as the research subjects. Based on the ultrasound findings, the fetuses were divided into ventricular dilatation group (n = 441), choroid plexus cyst group (n = 41), enlarged posterior fossa group (n = 42), holoprosencephaly group (n = 15), corpus callosum hypoplasia group (n = 22), and other anomaly group (n = 75). Meanwhile, they were also divided into isolated (n = 504) and non-isolated (n = 132) groups based on the presence of additional abnormalities. Prenatal samples (amniotic fluid/chorionic villi/umbilical cord blood) or abortus tissue were collected for the extraction of genomic DNA and CMA assay. Outcome of the pregnancies and postnatal follow-up were summarized and subjected to statistical analysis. RESULTS: In total 636 fetuses with CNS anomalies (including 89 abortus tissues) were included, and 547 cases were followed up. The overall detection rate of CMA was 11.48% (73/636). The detection rates for the holoprosencephaly group, ACC group, choroid plexus cyst group, enlarged posterior fossa group, ventricular dilatation group and other anomaly group were 80% (12/15), 31.82% (7/22), 19.51% (8/41), 14.29% (6/42), 7.48% (33/441) and 9.33% (7/75), respectively. Compared with the isolated CNS anomaly group, the detection rate for the non-isolated CNS anomaly group was significantly higher (6.35% vs. 31.06%) (32/504 vs. 41/132) (χ² = 62.867, P < 0.001). Follow up showed that, for 52 fetuses with abnormal CMA results, 51 couples have opted induced labor, whilst 1 was delivered at full term with normal growth and development. Of the 434 fetuses with normal CMA results, 377 were delivered at full term (6 had developmental delay), and 57 couples had opted induced labor. The rate of adverse pregnancy outcome for non-isolated CNS abnormal fetuses was significantly higher than that of isolated CNS abnormal fetuses (26.56% vs. 10.54%) (17/64 vs. 39/370) (χ² = 12.463, P < 0.001). CONCLUSION Fetuses with CNS anomaly should be tested with CMA to determine the genetic cause. Most fetuses with negative CMA result have a good prognosis, but there is still a possibility for a abnormal neurological phenotype. Fetuses with CNS abnormalities in conjunct with other structural abnormalities are at increased risk for adverse pregnancy outcomes.
Female ; Pregnancy ; Humans ; Holoprosencephaly ; Prenatal Diagnosis/methods* ; Central Nervous System ; Fetus/abnormalities* ; Nervous System Malformations/genetics* ; Microarray Analysis ; Central Nervous System Diseases ; Cysts ; Chromosome Aberrations ; Ultrasonography, Prenatal/methods*

OBJECTIVE: To explore the genetic basis for a child with facial dysmorphism and multiple malformations. METHODS: The child, born at 34⁺⁶ weeks' gestation due to premature rupture of amniotic membrane, dichorionic diamniotic twinning and gestational diabetes, was subjected to chromosomal karyotyping analysis and copy number variations sequencing (CNV-seq). RESULTS: The child was found to have facial dysmorphism, hypospadia, cryptorchidism and hypotonia. He was found to have a 46,XY,del(3)(p26) karyotype in addition with a 9.80 Mb deletion (chr3: 60 000-9 860 000) encompassing 33 protein coding genes. CONCLUSION The 3p26.3p25.3 deletion probably underlay the multiple malformations in this child. Continuous follow-up is required to improve his quality of life.
Humans ; Male ; Chromosome Deletion ; DNA Copy Number Variations ; Quality of Life ; Abnormalities, Multiple/genetics* ; Phenotype

OBJECTIVE: To explore the genetic basis of three children with unexplained developmental delay/intellectual disability (DD/ID). METHODS: Peripheral blood samples were collected from the patients and subjected to chromosomal microarray analysis (CMA). RESULTS: Patient 1 was found to harbor a 190 kb deletion at 9q34.3, which encompassed most of EHMT1 (OMIM 607001), the key gene for Kleefstra syndrome (OMIM 610253). Patients 2 and 3 were siblings. CMA showed that they have shared four chromosomal copy number variations (CNVs) including a deletion at 9q34.3 which spanned 154 kb and 149 kb, respectively, and encompassed the EHMT1 and CACNA1B (OMIM 601012) genes. The remaining 3 CNVs were predicted to be with no clinical significance. CONCLUSION Microdeletions at 9q33.4 probably underlay the pathogenesis of DD/ID in the three children, for which EHMT1 may be the key gene.
Child ; Chromosome Deletion ; Chromosomes, Human, Pair 9 ; Craniofacial Abnormalities/genetics* ; DNA Copy Number Variations ; Developmental Disabilities/genetics* ; Heart Defects, Congenital ; Humans ; Intellectual Disability/genetics*

OBJECTIVE: To report on a case of Smith-Magenis syndrome (SMS) due to a rare small-scale deletion. METHODS: Muscle samples from the the third fetus was collected after the in Medical history and clinical data of the patient were collected. The child and his parents were subjected to chromosome karyotyping analysis, multiplex ligation-dependent probe amplification (MLPA) and copy number variation sequencing (CNV-seq). RESULTS: The child was found to have a normal karyotype. MLPA and CNV-seq detection showed that he has harbored a 1.22 Mb deletion and a 0.3 Mb duplication in the 17p11.2 region. Neither of his parents was found to have similar deletion or duplication. CONCLUSION The child was diagnosed with SMS due to a rare 1.22 Mb deletion in the 17p11.2 region, which is among the smallest deletions associated with this syndrome.
Abnormalities, Multiple/genetics* ; Child ; Chromosome Deletion ; Chromosomes, Human, Pair 17 ; DNA Copy Number Variations ; Humans ; Intellectual Disability/genetics* ; Male ; Smith-Magenis Syndrome/genetics*

OBJECTIVE: To assess the diagnostic value of copy number variation sequencing (CNV-seq) in the genetic etiology of fetuses with nasal bone dysplasia (NBD). METHODS: A total of 217 fetuses discovered with NBD from December 2017 to December 2020 were divided into the isolated NBD group and NBD combined with other anomalies group, for which copy number variations (CNVs) were analyzed. RESULTS: A total of 40 fetal abnormalities were detected in 217 cases, with an overall abnormal rate of 18.4%. These included 31 cases with aneuploidies (14.3%, 31/217) and 9 cases with genomic CNVs (4.1%, 9/217). Five cases of trisomy 21 (3.5%, 5/144) and two CNVs cases with unknown clinical significance (1.4%, 2/144) were detected in the isolated group. As for the combined NBD group, 26 aneuploidies (35.6%, 26/73), including 19 cases with trisomy 21, 6 cases with trisomy 18, 1 case with trisomy 13, 5 cases with pathogenic CNVs (6.8%, 5/73), and 2 cases with CNVs of unknown clinical significance (2.7%, 2/73) were detected. A significant difference was detected between the two groups (P < 0.01). CONCLUSION The detection rate of CNV-seq is high for chromosomal aneuploidies and pathogenic CNVs in fetuses with NBD, particularly in those combined with other ultrasonic abnormalities.
Aneuploidy ; Bone Diseases, Developmental ; Chromosome Aberrations ; DNA Copy Number Variations ; Down Syndrome/genetics* ; Female ; Fetus/abnormalities* ; Humans ; Pregnancy ; Prenatal Diagnosis ; Trisomy

OBJECTIVE: To analyze the clinical and genetic features of three patient diagnosed with Kleefstra syndrome. METHODS: Whole exome sequencing (WES) was carried out for the probands and their parents. Suspected variants were validated by Sanger sequencing. Copy number variations (CNV) were detected by CNV-seq and validated by real-time PCR. RESULTS: Proband 1 was found to carry a de novo heterogeneous variant (c.823+1G>T) of the EHMT1 gene, which may affect its expression. Based on the guidelines of the American College of Medical Genetics and Genomics, the variant was predicted to be pathogenic (PVS1+PS2+PM2). Proband 2 was found to carry a de novo missense variant c.439C>G (p.L147V) of the EHMT1 gene, which was predicted to be likely pathogenic (PS2+PM1+PM2+PP3). Proband 3 was found to carry a heterozygous 520 kb deletion at 9q34.3 by CNV-seq. The deletion has encompassed the whole of the EHMT1 gene. Real-time PCR has detected no CNV of this region in her parents. CONCLUSION Variants of the EHMT1 gene probably underlay the disease in these patients. Genetic testing has provided a basis for their clinical diagnosis.
Chromosome Deletion ; Chromosomes, Human, Pair 9 ; Craniofacial Abnormalities ; DNA Copy Number Variations ; Female ; Genetic Testing ; Heart Defects, Congenital ; Humans ; Intellectual Disability/genetics* ; Mutation

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 delineate the nature and origin of chromosomal aberration in a boy with mental retardation and multiple congenital deformities. METHODS: Chromosomal karyotypes of the proband and his parents were determined by routine G-banding analysis. Genomic DNA was also analyzed with single nucleotide polymorphism array (SNP array). RESULTS: The karyotype of the proband was 46,X,add(Y)(q11.23). No karyotypic abnormality was detected in either parent. SNP array has identified a de novo 21.6 Mb duplication at 22q12qter in the proband. CONCLUSION The de novo 22q12qter duplication probably underlies the abnormalities in the proband.
Abnormalities, Multiple ; genetics ; Adult ; Child ; Chromosome Banding ; Chromosomes, Human, Pair 22 ; genetics ; Female ; Genetic Testing ; Humans ; Intellectual Disability ; genetics ; Karyotyping ; Male ; Trisomy

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 assess the clinical application of single nucleotide polymorphism microarray (SNP array) in prenatal genetic diagnosis for fetuses with absent nasal bone. METHODS: Seventy four fetuses with absent nasal bone detected by prenatal ultrasound scanning were recruited from Women's Hospital, Zhejiang University School of Medicine during June 2015 and October 2018. The chromosome karyotypes analysis and SNP array were performed. The correlation between absent fetal nasal bone and chromosome copy number variants was analyzed. RESULTS: Among 74 fetuses, 19 were detected to have chromosomal abnormalities, including 16 cases of trisomy-21, 1 case of trisomy-18 and two cases of micro-deletion/duplication. Among 46 cases with isolated absence of nasal bone, 3 had trisomy-21, and 1 had a micro-duplication. Absence of nasal bone in association with nuchal translucency thickening had a higher rate of abnormal karyotypes compared with isolated absence of nasal bone (=32.27,<0.01). CONCLUSIONS Fetuses with absent nasal bone and nuchal translucency thickening are likely to have chromosome abnormalities, and SNP array testing is recommended to exclude the chromosome abnormalities.
Chromosome Aberrations ; Female ; Fetus ; Humans ; Nasal Bone ; abnormalities ; Oligonucleotide Array Sequence Analysis ; standards ; Polymorphism, Single Nucleotide ; genetics ; Pregnancy ; Pregnancy Trimester, First ; Prenatal Diagnosis ; methods