OBJECTIVE: The study aimed to estimate the benchmark dose (BMD) of coke oven emissions (COEs) exposure based on mitochondrial damage with the mitochondrial DNA copy number (mtDNAcn) as a biomarker. METHODS: A total of 782 subjects were recruited, including 238 controls and 544 exposed workers. The mtDNAcn of peripheral leukocytes was detected through the real-time fluorescence-based quantitative polymerase chain reaction. Three BMD approaches were used to calculate the BMD of COEs exposure based on the mitochondrial damage and its 95% confidence lower limit (BMDL). RESULTS: The mtDNAcn of the exposure group was lower than that of the control group (0.60 ± 0.29 vs. 1.03 ± 0.31; P < 0.001). A dose-response relationship was shown between the mtDNAcn damage and COEs. Using the Benchmark Dose Software, the occupational exposure limits (OELs) for COEs exposure in males was 0.00190 mg/m ³. The OELs for COEs exposure using the BBMD were 0.00170 mg/m ³ for the total population, 0.00158 mg/m ³ for males, and 0.00174 mg/m ³ for females. In possible risk obtained from animal studies (PROAST), the OELs of the total population, males, and females were 0.00184, 0.00178, and 0.00192 mg/m ³, respectively. CONCLUSION Based on our conservative estimate, the BMDL of mitochondrial damage caused by COEs is 0.002 mg/m ³. This value will provide a benchmark for determining possible OELs.
Male ; Female ; Animals ; Coke ; Polycyclic Aromatic Hydrocarbons ; DNA Copy Number Variations ; Benchmarking ; Occupational Exposure/analysis* ; DNA, Mitochondrial/genetics* ; DNA Damage

OBJECTIVE: To analyze the clinical phenotype and genetic variant of a child with Snijders Blok-Campeau syndrome (SBCS). METHODS: A child who was diagnosed with SBCS in June 2017 at Henan Children's Hospital was selected as the study subject. Clinical data of the child was collected. Peripheral blood samples of the child and his parents were collected and the extraction of genomic DNA, which was subjected to trio-whole exome sequencing (trio-WES) and genome copy number variation (CNV) analysis. Candidate variant was verified by Sanger sequencing of his pedigree members. RESULTS: The main clinical manifestations of the child have included language delay, intellectual impairment and motor development delay, which were accompanied with facial dysmorphisms (broad forehead, inverted triangular face, sparse eyebrows, widely spaced eyes, narrow palpebral fissures, broad nose bridge, midface hypoplasia, thin upper lip, pointed jaw, low-set ears and posteriorly rotated ears). Trio-WES and Sanger sequencing revealed that the child has harbored a heterozygous splicing variant of the CHD3 gene, namely c.4073-2A>G, for which both of his parents were of wild-type. No pathogenic variant was identified by CNV testing. CONCLUSION The c.4073-2A>G splicing variant of the CHD3 gene probably underlay the SBCS in this patient.
DNA Copy Number Variations ; Heterozygote ; Pedigree ; Phenotype ; RNA Splicing ; Mutation

OBJECTIVE: To analyze the prognosis of fetuses identified with de novo variants of unknown significance (VOUS) by chromosome microarray analysis (CMA). METHODS: A total of 6 826 fetuses who underwent prenatal CMA detection at the Prenatal Diagnosis Center of Drum Tower Hospital from July 2017 to December 2021 were selected as the study subjects. The results of prenatal diagnosis, and outcome of fetuses identified with VOUS of de novo origin were followed up. RESULTS: Among the 6 826 fetuses, 506 have carried VOUS, of which 237 were detected for the parent-of-origin and 24 were found to be de novo. Among the latters, 20 were followed up for 4 to 24 months. Four couples had opted elective abortion, 4 had developed clinical phenotypes after birth, and 12 were normal. CONCLUSION Fetuses with VOUS should be continuously follow-up, in particular those carrying de novo VOUS, in order to clarify their clinical significance.
Pregnancy ; Female ; Humans ; DNA Copy Number Variations ; Follow-Up Studies ; Prenatal Diagnosis/methods* ; Chromosomes ; Microarray Analysis/methods* ; Fetus ; Chromosome Aberrations

OBJECTIVE: To explore the genetic etiology and related factors in 1 065 women with spontaneous abortions. METHODS: All patients have presented at the Center of Prenatal Diagnosis of Nanjing Drum Tower Hospital from January 2018 to December 2021. Chorionic villi and fetal skin samples were collected, and the genomic DNA was assayed by chromosomal microarray analysis (CMA). For 10 couples with recurrent spontaneous abortions but normal CMA results for abortive tissues, non-in vitro fertilization-embryo transfer (IVF-ET) pregnancies and no previous history of live births and no structural abnormalities of the uterus, peripheral venous blood samples were collected. Genomic DNA was subjected to trio-whole exome sequencing (trio-WES). Candidate variants were verified by Sanger sequencing and bioinformatics analysis. Multifactorial unconditional logistic regression analysis was carried out to analyze the factors that may affect chromosomal abnormality in spontaneous abortions, such as the age of the couple, number of previous spontaneous abortions, IVF-ET pregnancy and history of live birth. The incidence of chromosomal aneuploidies in spontaneous abortions during the first trimester was compared in young or advanced-aged patients by chi-square test for liner trend. RESULTS: Among the 1 065 spontaneous abortion patients, 570 cases (53.5%) of chromosomal abnormalities were detected in spontaneous abortion tissues, which included 489 cases (45.9%) of chromosomal aneuploidies and 36 cases (3.4%) of pathogenic/likely pathogenic copy number variations (CNVs). Trio-WES results have revealed one homozygote variant and one compound heterozygote variants in two pedigrees, both of which were inherited from the parents. One likely pathogenic variant was detected in the patient from two pedigrees. Multifactorial unconditional Logistic regression analysis suggested that age of patient was an independent risk factor of chromosome abnormalities (OR = 1.122, 95%CI: 1.069-1.177, P < 0.001), the number of previous abortions and IVF-ET pregnancy were independent protective factors for chromosomal abnormalities (OR = 0.791, 0.648; 95%CI: 0.682-0.916, 0.500-0.840; P = 0.002, 0.001), whilst the age of husband and history of live birth were not (P > 0.05). The incidence of aneuploidies in the abortive tissues has decreased with the number of previous spontaneous abortions in young patients (χ² = 18.051, P < 0.001), but was not significantly correlated with the number of previous spontaneous abortions in advanced-aged patients with spontaneous abortions (P > 0.05). CONCLUSION Chromosomal aneuploidy is the main genetic factor for spontaneous abortion, though CNVs and genetic variants may also underlie its genetic etiology. The age of patients, number of previous abortions and IVF-ET pregnancy are closely associated with chromosome abnormalities in abortive tissues.
Pregnancy ; Humans ; Female ; Aged ; Abortion, Spontaneous/genetics* ; DNA Copy Number Variations ; Chromosome Aberrations ; Chromosome Disorders/genetics* ; Aneuploidy ; Abortion, Habitual/genetics*

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 fetus with bilateral lateral ventriculomegaly. METHODS: Fetus umbilical cord blood and peripheral blood samples of its parents were collected. The fetus was subjected to chromosomal karyotyping, whilst the fetus and its parents were subjected to array comparative genomic hybridization (aCGH). The candidate copy number variation (CNV) were verified by qPCR, Application goldeneye DNA identification system was used to confirm the parental relationship. RESULTS: The fetus was found to have a normal karyotype. aCGH analysis indicated that it has carried a 1.16 Mb deletion at 17p13.3, which partially overlapped with the critical region of Miller-Dieker syndrome (MDS), in addition with a 1.33 Mb deletion at 17p12 region, which is associated with hereditary stress-susceptible peripheral neuropathy (HNPP). Its mother was also found to harbor the 1.33 Mb deletion at 17p12. qPCR analysis confirmed that the expression levels of genes from the 17p13.3 and 17p12 regions were about the half of that in the normal control, as well as the maternal peripheral blood sample. Parental relationship was confirmed between the fetus and its parents. Following genetic counseling, the parents has chosen to continue with the pregnancy. CONCLUSION The fetus was diagnosed with Miller-Dieker syndrome due to the de novo deletion at 17p13.3. Ventriculomegaly may be an important indicator for prenatal ultrasonography in fetuses with MDS.
Pregnancy ; Female ; Humans ; Classical Lissencephalies and Subcortical Band Heterotopias ; Comparative Genomic Hybridization ; DNA Copy Number Variations ; Fetus ; Hydrocephalus ; Prenatal Diagnosis ; Chromosome Deletion

OBJECTIVE: To assess the value of chromosomal microarray analysis (CMA) and trio-whole exome sequencing (trio-WES) for fetuses with increased nuchal translucency (NT) thickness. METHODS: Sixty two pregnant women who had visited Urumqi Maternal and Child Care Health Hospital between June 2018 and June 2020 for NT ≥ 3.0 mm at 11 ~ 13⁺⁶ gestational weeks were selected as study subjects. Relevant clinical data were collected. The patients were divided into 3.0 ~ ＜3.5 mm (n = 33) and ≥3.5 mm groups (n = 29). Chromosome karyotyping analysis and chromosomal microarray analysis were carried out. And trio-WES analysis was performed on 15 samples with NT thickening but negative CMA results. The distribution and incidence of chromosomal abnormalities in the two groups were compared by using chi-square test. RESULTS: The median age of the pregnant women was 29 years old (22 ~ 41 years old), the median thickness of NT was 3.4 mm (3.0 ~ 9.1 mm), and the median gestational age at the detection was 13⁺⁴ weeks (11⁺⁵ ~ 13⁺⁶ weeks). Chromosome karyotyping analysis has detected 12 cases of aneuploidies and 1 case of derivative chromosome. The detection rate was 20.97% (13/62). CMA has detected 12 cases of aneuploidies, 1 case of pathogenic CNV and 5 cases of variant of uncertain significance (VUS), with a detection rate of 29.03% (18/62). The aneuploidy rate for the NT ≥ 3.5 mm group was higher than that for the 3.0 ≤ NT < 3.5 mm group [3.03% (1/33) vs. 41.38% (12/29), χ² = 13.698, P < 0.001]. There was no statistically significant difference between the two groups in the detection rate of fetal pathogenic CNV and VUS (χ² = 0.028, P > 0.05). Trio-WES analysis of 15 samples with negative CMA result and no structural abnormality has identified 6 heterozygous variants, including SOS1: c.3542C>T (p.A1181V) and c.3817C>G (p.L1273V), COL2A1: c.436C>T (p.P146S) and c.3700G>A (p.D1234N), LZTR1: c.1496T>C (p.V499A), and BRAF: c.64G>A (p.D22N), respectively. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), all of the variants were rated as VUS. CONCLUSION NT thickening can indicate chromosome abnormality, and CMA and trio-WES may be used for the prenatal diagnosis.
Pregnancy ; Humans ; Female ; Adult ; Infant ; Nuchal Translucency Measurement/methods* ; Prenatal Diagnosis/methods* ; Chromosome Aberrations ; Aneuploidy ; Fetus/diagnostic imaging* ; Ultrasonography, Prenatal ; DNA Copy Number Variations ; Transcription Factors

OBJECTIVE: To explore the genetic basis for a fetus with Cardiac-urogenital syndrome (CUGS). METHODS: A fetus with congenital heart disease identified at the Maternal Fetal Medical Center for Fetal Heart Disease, Beijing Anzhen Hospital Affiliated to Capital Medical University in January 2019 was selected as the study subject. Clinical data of the fetus was collected. Copy number variation sequencing (CNV-seq) and trio-whole exome sequencing (trio-WES) were carried out for the fetus and its parents. Candidate variants were verified by Sanger sequencing. RESULTS: Detailed fetal echocardiographic examination had revealed hypoplastic aortic arch. The results of trio-WES revealed that the fetus has harbored a de novo splice variant of the MYRF gene (c.1792-2A>C), for which both parents were of the wild-type. Sanger sequencing confirmed the variant to be de novo. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was rated as likely pathogenic. CNV-seq has identified no chromosomal anomalies. And the fetus was diagnosed with Cardiac-urogenital syndrome. CONCLUSION The de novo splice variant of the MYRF gene probably underlay the abnormal phenotype in the fetus. Above finding has enriched the spectrum of MYRF gene variants.
Female ; Humans ; DNA Copy Number Variations ; Fetal Diseases ; Fetus/abnormalities* ; Heart Defects, Congenital/genetics* ; Mutation ; Transcription Factors/genetics*

OBJECTIVE: To explore the strategies of prenatal diagnosis and genetic counseling for fetuses of two families with large deletions of 13q21. METHODS: Two singleton fetuses who were diagnosed with chromosome 13 microdeletions by non-invasive prenatal testing (NIPT) at Ningbo Women and Children's Hospital in March 2021 and December 2021 respectively were selected as the study subjects. Chromosomal karyotyping and chromosomal microarray analysis (CMA) were carried on amniotic samples. Peripheral blood samples were collected from the two couples for CMA assay to determine the origin of abnormal chromosomes identified in the fetuses. RESULTS: The karyotypes of the two fetuses were both normal. CMA revealed that they have respectively harbored heterozygous deletions spanning 11.935 Mb at 13q21.1q21.33 and 10.995 Mb at 13q14.3q21.32, which were respectively inherited from their mother and father. Both deletions had low gene density and lacked haploinsufficient genes, and were predicted to be likely benign variants based on database and literature search. Both couples had opted to continue with the pregnancy. CONCLUSION The deletions of the 13q21 region in both families may be of benign variants. As the follow-up time was short, there was no sufficient evidence for the determination of pathogenicity, though our finding may still provide a basis for the prenatal diagnosis and genetic counseling.
Pregnancy ; Child ; Female ; Humans ; Pedigree ; East Asian People ; Prenatal Diagnosis ; Chromosome Aberrations ; Karyotyping ; Microarray Analysis ; DNA Copy Number Variations

OBJECTIVE: To analyze the clinical phenotype and genetic etiology for a child featuring congenital hypothyroidism (CH). METHODS: Whole exome sequencing (WES), copy number variation (CNV) sequencing and chromosomal microarray analysis (CMA) were carried out for a newborn infant who had presented at Linyi People's Hospital for CH. Clinical data of the child was analyzed, in addition with a literature review. RESULTS: The main characteristics of the newborn infant had included peculiar face, vulvar edema, hypotonia, psychomotor retardation, recurrent respiratory tract infection with laryngeal wheezing and feeding difficulties. Laboratory test indicated hypothyroidism. WES suggested a CNV deletion on chromosome 14q12q13. CMA further confirmed a 4.12 Mb deletion at chromosome 14q12q13.3 (32649595_36769800), which has encompassed 22 genes including NKX2-1, the pathogenic gene for CH. The same deletion was found in neither of her parents. CONCLUSION Through the analysis of clinical phenotype and genetic variant, the child was diagnosed with 14q12q13.3 microdeletion syndrome.
Female ; Humans ; Congenital Hypothyroidism/genetics* ; DNA Copy Number Variations ; Phenotype ; Syndrome ; Microarray Analysis