Prenatal diagnosis of Coffin-Siris syndrome: What are the fetal features?

OBJECTIVE: To present both our center's and previously reported experience of prenatal diagnosis of Coffin-Siris syndrome (CSS) with regard to the laboratory testing and fetal features of this syndrome. METHODS: This was a retrospective study of eight pregnancies with fetal CSS identified by prenatal or postnatal genetic testing. Clinical and laboratory data were collected and reviewed for these cases, including maternal demographics, prenatal sonographic findings, chromosomal microarray and exome sequencing (ES) results, and pregnancy outcomes. RESULTS: A total of eight cases of fetal CSS based on molecular testing were detected. Two cases presented with an increased nuchal translucency (NT) in the first trimester. The remaining six were identified at the second trimester scan. Agenesis of the corpus callosum (ACC) was the most common sonographic finding, accounting for 5/7 (71.4%) cases in which a second trimester sonogram was performed: four had ACC as an isolated finding, and one had additional features of cerebellar hypoplasia and left congenital diaphragmatic hernia. CONCLUSION: CSS should be included in the differential diagnosis when ACC is found by prenatal ultrasound. Both chromosomal microarray and ES should be options when counseling patients with a structurally anomalous fetus.

Prenatal sonographic findings in a cohort of foetuses with a confirmed 22q11.2 microdeletion at a single Chinese Tertiary Centre.

The aim of this study was to present prenatal ultrasound findings, molecular testing results and pregnancy outcomes of cases with 22q11.2 deletion (del22q11.2) diagnosed prenatally. A total of 76 foetuses were included. All cases were diagnosed by using chromosomal microarray analysis. Data on prenatal diagnosis, ultrasound findings, pregnancy outcomes and inheritance of del22q11.2 were reviewed. Congenital heart defects (CHDs) were the most common indications (47/76, 61.8%) for prenatal testing and were isolated in 52.6% (40/76). The constitution of CHDs comprised predominantly of conotruncal defects (61.7%; 29/47). Other cardiac anomalies were encountered in 38.3% (18/47) of cases. Extracardiac findings, including unilateral multicystic dysplastic kidney, clubfoot, increased nuchal translucency, intrauterine growth retardation and polyhydramnios, were found in 31.6% (24/76) of cases, and were combined with CHDs in 7 cases. Twelve cases had normal sonographic scans at the time of prenatal diagnosis. Foetal CHDs, especially conotruncal defects, are the most predictive association with del22q11.2. The information about del22q11.2 should also be part of the contents in comprehensive pre-test counselling even for those who are referred for diagnostic testing with foetal extracardiac findings.Impact statementWhat is already known on this subject? 22q11.2 deletion (del22q11.2) is the most common microdeletion syndrome in humans. At present, the main indications for prenatal testing for del22q11.2 are pregnancies of abnormal sonographic findings, especially foetal congenital heart defects.What do the results of this study add? Many extracardiac malformations, including some lethal or mildly non-specific ones, could be associated with foetal del22q11.2. There were also del22q11.2 foetuses had normal sonographic scans at the time of prenatal diagnosis.What are the implications of these findings for clinical practice and/or further research? The information about del22q11.2 should also be part of the contents in comprehensive pre-test counselling even for those who are referred for diagnostic testing with indications other than foetal cardiac anomalies.

[Genetic analysis and prenatal diagnosis of a fetus with Xq25 microduplication].

OBJECTIVE: To explore the genetic basis for a fetus with structural brain abnormalities. METHODS: The karyotypes of the fetus and its parents were analyzed by conventional G-banding. Chromosome microarray analysis (CMA) was carried out to detect chromosomal microdeletion and microduplication. RESULTS: No kartotypic abnormality was detected in the fetus and its parents. CMA has identified a 194 kb microduplication at Xq25 in the fetus, which encompassed exons 4-35 of the STAG2 gene and was derived from its mother. CONCLUSION: The Xq25 duplication encompassing part of the STAG2 gene probably underlay the brain malformation in the fetus.

Compound heterozygous mutation of the ASXL3 gene causes autosomal recessive congenital heart disease.

To explore mutations in the additional sex combs-like 3 (ASXL3) gene in two Chinese families with congenital heart disease (CHD). Whole-exome sequencing (WES) was used to reveal a novel compound heterozygous mutation in the ASXL3 gene that was associated with CHD. Sanger sequencing of a further 122 CHD patients was used to determine an additional compound heterozygous mutation in the ASXL3 gene. Cell apoptosis was examined by MTS assay and flow cytometry. The cardiac structure was identified via hematoxylin-eosin (HE), Masson's trichrome, and ultrasound scanning. RNA sequencing was performed to identify a series of differentially expressed mRNAs. The mRNA and protein expressions were identified by quantitative real-time PCR and western blotting, respectively. A compound heterozygous mutation c.2168C > G (p.Pro723Arg) and c.5449C > G (p.Pro1817Ala) in the ASXL3 gene associated with CHD was identified. Overexpression of this compound heterozygous mutation in HL-1 cells resulted in increased apoptosis and reduced cell viability. Moreover, it affected cardiac structure and fibrosis in mice. There were 126 downregulated mRNAs and 117 upregulated mRNAs between the ASXL3 compound heterozygous mutation c.2168C > G (p.Pro723Arg) and c.5449C > G (p.Pro1817Ala) mice and wild-type mice. Ezh2, Slc6a4, and Socs3, which could interact with ASXL3 through proteins, were all upregulated. Another compound heterozygous mutation c.3526C > T (p.Arg1176Trp) and c.4643A > G (p.Asp1548Gly) in the ASXL3 gene was identified by screening a further 122 patients with CHD. The ASXL3 gene is important in cardiac development and may exert this influence by affecting the expression of mRNAs associated with cell apoptosis and cell proliferation.

[Value of chromosomal microarray analysis for fetuses with duodenal obstruction].

OBJECTIVE: To assess the value of chromosomal microarray analysis (CMA) for fetal duodenal obstruction (DO). METHODS: Fifty-one fetuses with DO identified by prenatal ultrasound were divided into DO only group and DO with other anomaly group. CMA was carried out on amniotic fluid or umbilical blood samples, and the outcome of pregnancy of all cases were followed up. RESULTS: Eight fetuses (15.7%) were found with genomic abnormalities, which included 3 chromosomal aneuploidies and 5 copy number variations (CNVs), including one 17q12 microduplication syndrome, one 13q21.33q31.1 microdeletion, one 13q21.32q22.3 deletion, one 13q21.2q31.1 deletion and one 1q43q44 duplication. EDNRB from 13q and HNF1B from 17q12 are candidate genes for fetal DO. No significant difference was found in the detection rate of pathogenic CNVs between the DO only and DO with other anomaly groups (9.5% vs.11.1%, P> 0.05). There were 39 live borns, 1 stillbirth, and 11 artificial abortions (8 with abnormal CMA results). CONCLUSION: There is a correlation between fetal DO and abnormal copy number of the genome, for which prenatal diagnosis is necessary. CMA not only can detect microdeletions/microduplications, but also identify pathogenic genes, which can facilitate prenatal diagnosis, genetic counseling and prognosis for the fetus.

[Application of whole exome sequencing technology in fetuses with congenital structural abnormalities].

OBJECTIVE: To investigate the application value of whole exome sequencing technology in fetuses with congenital structural abnormalities. METHODS: The chromosomal abnormalities of 1147 families were analyzed. According to the follow-up results, the data of fetuses with new phenotypes in late pregnancy or after birth were reanalyzed. Subgroups were divided according to the organs involved and whether single malformation or not. The gene regulatory network map was drawn by using string database and Cytoscape software. Fisher exact probability method was used to compare the difference of the diagnostic rate of pathogenic genes among the groups. RESULTS: A total of 160 fetal cases received positive molecular diagnosed, involving 178 variant sites of 125 pathogenic genes, including 8 cases (4.9%, 8/163) by data reanalysis, and the overall positive diagnosis rate was 13.9%. Diagnostic rate was highest in the group of skeletal malformation (31.5%, 39/124) and lowest in that with thoracic malformation (0, 0/32). The gene clusters of fetal edema and intrauterine growth restriction were independent, and were not associated with the major structural malformations. The probability of each parent carrying the same recessive gene variant was 0.03 (39/1146) and 0.08 (4/53) with positive family history. CONCLUSION: For fetuses with congenital structural abnormalities that are negative for conventional genetic tests, 13.9% of phenotypic associated pathogenic/likely pathogenic genetic variants can be detected by whole exome sequencing technology. Its application value for prenatal diagnosis varies in fetus with different organs involved. Reanalysis of sequencing data for cases with new phenotypes in late pregnancy or after birth can further improve the molecular diagnosis rate. Further investigations are needed to explore the related genetic mechanisms.

Prenatal exome sequencing in fetuses with congenital heart defects.

The genetic diagnosis of congenital heart defects (CHDs) is challenging because of genetic and phenotypic heterogeneity. The aim of our study was to evaluate the clinical value of whole exome sequencing (WES) in the prenatal diagnosis of CHDs in a large cohort. Trio-based WES was performed in 260 fetuses with CHDs negative for karyotype and chromosome microarray analysis results. WES produced a diagnostic yield of 10% (26/260) in the entire cohort. Relative high diagnostic rate was observed in cases with cardiac rhabdomyoma (60%), complex CHDs (16.7%), septal defect (14.0%), and conotruncal defect (9.9%). There was no significant difference between the diagnostic yields in simple and complex CHDs groups (9.9% vs 16.7%), and in non-isolated and isolated CHDs groups (15.7% vs 7.9%). The diagnostic yields in cases with CHDs with soft markers, CHDs with fetal growth restriction, and CHDs with other structural anomalies (syndromic CHDs) were 0 (0/13), 50% (1/2) and 18.2% (10/55), respectively. Variants of unknown significance were detected in 16 (6.2%) fetuses, and secondary findings in 7 (2.7%) cases. Variants in 14 candidate genes were identified. Our study demonstrates an incremental diagnostic yield by trio-based WES in the prenatal diagnosis of CHDs after routine tests, not as high as expected.

Genetic tests aid in counseling of fetuses with cerebellar vermis defects.

OBJECTIVE: To assess the value of chromosome microarray analysis (CMA) and whole exome sequencing (WES) in fetuses with cerebellar vermis defects (CVD). METHODS: From 2013 to 2019, we performed CMA on 43 fetuses with CVD, who were divided into cerebellar vermis hypoplasia (CVH) group and Dandy-Walker malformation (DWM) group according to morphological subtypes. Subsequently, WES was performed on 19 fetuses with normal CMA results to identify diagnostic genetic variants (DGVs). RESULTS: Chromosome aneuploidies and clinically significant copy number variants were identified in 23.3% (10/43) of fetuses, and a significantly higher positive rate was found in fetuses with multiple compared with isolated malformations (36% vs 5.6%, P = .028). STAG2 genes related to Xq25 duplication syndrome was possibly a novel candidate gene for CVD. WES detected eight DGVs in seven genes among the 19 fetuses tested. Autosomal recessive ciliopathies (4/8) caused by TMEM231, CSPP1, and CEP290 mutations, were the most frequent monogenetic diseases, followed by Opitz GBBB syndrome (2/8) caused by MID1 and SPECC1L variants. CONCLUSION: The combined use of CMA and WES has the potential to provide genetic diagnoses in 42% (18/43) of fetal CVD. WES should be offered when CMA results are normal.

Prenatal diagnosis of 17q12 deletion syndrome: a retrospective case series.

The 17q12 deletion syndrome is a chromosomal anomaly resulting from the interstitial microdeletion of the long arm of chromosome 17. The aim of this study was to present the experience on prenatal diagnosis of 17q12 deletion to further define the prenatal phenotypes of this syndrome. Eleven pregnancies with foetal 17q12 deletion detected by chromosomal microarray (CMA) were retrospectively included at a single Chinese tertiary medical centre. Clinical data were reviewed for these cases, including the maternal demographics, foetal ultrasound findings, CMA results and pregnancy outcomes. The deletion sizes of 17q12 ranged from 1.42 to 1.94 Mb. The deletion had arisen de novo in 10 cases and inherited from one of the parents in one case. Variable kidney abnormalities were found by ultrasound in all of the cases, with bilateral or unilateral hyperechogenic kidneys being the most common findings. This study indicates that a strikingly high correlation between prenatal hyperechogenic kidneys and 17q12 deletion, and prenatal testing with CMA should be offered to the foetal cases of hyperechogenic kidneys. Impact statement What is already known on this subject? 17q12 deletion syndrome is a cause of renal abnormalities, maturity-onset diabetes of the young and neurodevelopmental disorders. Prenatal diagnosis has been reported in several isolated cases with the use of microarray-based technologic means. What do the results of this study add? The results provide further evidence that a strikingly high correlation between prenatal hyperechogenic kidneys and 17q12 deletion, and genetic testing should be offered to foetal cases with hyperechogenic kidneys. A rare prenatal case of 17q12 deletion with multiple structural malformations and anhydramnios is presented. What are the implications of these findings for clinical practice and/or further research? There should be a high index of suspicion of carriers in parents when 17q12 deletion is confirmed prenatally. An extremely wide phenotype spectrum of this deletion should be emphasised in the prenatal counselling.

[Clinical and genetic analysis of three pediatric patients with 15q24 microdeletion syndrome].

OBJECTIVE: To explore the genetic basis for three patients with development delay and to correlate their clinical phenotypes with genetic findings. METHODS: The karyotypes of the probands and their parents were analyzed by conventional G-banding. Chromosomal microarray analysis (CMA) was used to detect microdeletion and microduplication. RESULTS: No kartotypic abnormality was detected in the patients and their parents. CMA analysis identified a de novo 3.10 Mb deletion on chromosome 15q24.1q24.2 in case 1, a de novo 3.14 Mb deletion at 15q24.1q24.2 in case 2, and a 3.13 Mb deletion at 15q24.1q24.2 in case 3. All deletions have encompassed the CPLX3,SEMA7A and SIN3A genes. CONCLUSION: The three patients were diagnosed with 15q24 microdeletion syndrome. CPLX3,SEMA7A and SIN3A may be the key genes responsible for this syndrome.

[Clinical and molecular genetic analysis of a pediatric patient with Lowe syndrome].

OBJECTIVE: To explore the genetic etiology for a child with ocular dysplasia. METHODS: Clinical examination was carried out. Medical history of the child was collected. Genomic DNA was extracted from peripheral blood samples. Chromosomal microarray analysis (CMA) was used to detect potential genomic copy number variations. RESULTS: Ultrasonography revealed cataracts in both eyes of the child. MRI showed increased extracranial space, supratentorial ventricular dilatation, reduced white matter volume, increased T2WI signal and a large occipital cisterna. CMA showed that the patient carried a 249 kb microdeletion at Xq25q26.1 region, namely [hg19]arrXq25q26.1 (128 652 372 - 128 901 629)×0. CONCLUSION: The child was diagnosed with Lowe syndrome, for which the 249 kb microdeletion at Xq25q26.1 is probably accountable.

Pregnancy outcome of autosomal aneuploidies other than common trisomies detected by noninvasive prenatal testing in routine clinical practice.

OBJECTIVE: The objective of the study is to report the incidence and pregnancy outcome of autosomal aneuploidies other than common trisomies 21, 18, and 13 detected by noninvasive prenatal testing (NIPT) at a single center. METHODS: Pregnant women undergoing NIPT from February 2015 to January 2018 in our center were offered expanded screening to include rare autosomal aneuploidies. Aneuploidies included extra copy chromosomes (most likely trisomies) and decreased copy chromosomes (most likely monosomies). The pregnancy outcomes of women consenting to the expanded NIPT screen were recorded. RESULTS: Expanded NIPT was performed in 15 362 pregnancies. A total of 59 autosomal aneuploidies other than the 3 common trisomies were detected, with a positive screening rate of 0.38% (59/15 362). The screen positive rate was higher in women aged above 35 years than in those younger (0.44% vs 0.32%, P < .05). Of the screen positive results, 30.5% (18/59) were because of extra copies for chromosomes trisomy 7, 10.2% (6/59) for chromosome 22, and 8.5% (5/59) for chromosomes 8 and 16 respectively, while other choromosomes were less frequently involved. Decreased copy chromosomes were less common: 6.8% (4/59) for chromosomes 14 and 13. Mixed aneuploidies with increased copies for some chromosomes and decreased copies for others were also noted. Invasive prenatal diagnosis was performed in 61% (36/59) of the cases. Invasive test results and clinical follow-ups demonstrated that most (94.9%, 56/59) of the rare aneuploidies were false positives, probably resulting from confined placental mosaicism. Only 1 case (1.7%, 1/59) with NIPT report of extra copies of chromosome 7 and without ultrasound evidence of fetal abnormality was confirmed to be fetal mosaicism by microarray test. Uniparental disomy of whole chromosome 2 was identified by microarray analysis in 1 case with extra copy chromosome 2 detected by NIPT. Loss of heterozygocity of chromosome 7q11.23-q21.11 was detected in another case with extra copy chromosome 7. Fortunately, pregnancy outcomes of both cases were normal. Two fetal deaths attributed to severe fetal growth restriction were associated with extra copies of chromosome 16 at expanded NIPT. CONCLUSIONS: Autosomal aneuploidies other than trisomies 21, 18, and 13 are not uncommon in routine clinical NIPT practice. Extra copies of chromosomes in rare cases can be associated with uniparental disomy. Most rare aneuploidies at NIPT have good pregnancy outcomes. Thus, invasive testing should be used with caution for these aneuploidies in routine clinical practice.

Whole-exome sequencing for prenatal diagnosis of fetuses with congenital anomalies of the kidney and urinary tract.

BACKGROUND: In the absence of cytogenetic abnormality, fetuses with congenital anomalies of the kidney and urinary tract (CAKUT) with/without other structural anomalies show a higher likelihood of monogenic causes; however, defining the underlying pathology can be challenging. Here, we investigate the value of whole-exome sequencing (WES) in fetuses with CAKUT but normal findings upon karyotyping and chromosome microarray analysis. METHODS: WES was performed on DNA from the cord blood of 30 fetuses with unexplained CAKUT with/without other structural anomalies. In the first 23 cases, sequencing was initially performed on fetal DNA only; for the remaining seven cases, the trio of fetus, mother and father was sequenced simultaneously. RESULTS: Of the 30 cases, pathogenic variants were identified in 4 (13%) (UMOD, NEK8, HNF1B and BBS2) and incidental variants in 2 (7%) (HSPD1 and GRIN2B). Furthermore, two of the above four cases had other anomalies in addition to CAKUT. Thus, the detection rate was only 2/22 (9.1%) for isolated CAKUT and 2/8 (25%) for CAKUT with other abnormalities. CONCLUSIONS: Applying WES to the prenatal diagnostic approach in CAKUT fetuses with or without other anomalies allows for an accurate and early etiology-based diagnosis and improved clinical management. To expedite interpretation of the results, trio sequencing should be employed; however, interpretation may nevertheless be compromised by incomplete coverage of all relevant genes.

Clinical application of SNP array analysis in fetuses with ventricular septal defects and normal karyotypes.

PURPOSE: The present study aims to evaluate the utility of high-resolution single-nucleotide polymorphism (SNP) arrays in fetuses with ventricular septal defects (VSDs) with or without other structural anomalies but with normal karyotypes and to investigate the outcomes of cases of prenatal VSDs via clinical follow-up. METHODS: We analyzed 144 fetuses with VSDs and normal karyotypes using Affymetrix CytoScan HD arrays and the analyses were carried out a year after birth. RESULTS: Clinically significant CNVs were detected in 12 fetuses (8.3%). The most common pathogenic CNV was a 22q11.2 deletion with a detection rate of 2.8% (4/144). Well-known microdeletion or microduplication syndromes, including Smith-Magenis, Miller-Dieker, 9q subtelomeric deletion, 1p36 microdeletion, 1q21.1 microduplication, and terminal 4q deletion syndrome, were identified in six cases. Three regions of chromosomal imbalance were also identified: microduplication at 12q24.32q24.33, microdeletion at 16p13.13p13.12 and microdeletion at Xp21.1. The genes TBX1, SKI, GJA5, EHMT1, NOTCH1 were identified as established genes and LZTR1, PRDM26, YWHAE, FAT1, AKAP10, ERCC4, and ULK1 were identified as potential candidate genes of fetal VSDs. There was no significant difference in pathogenic CNVs between isolated VSDs and VSDs with additional structural abnormalities. Ninety-five (74.8%) pregnant women with fetuses with benign CNVs chose to continue the pregnancy and had a favorable prognosis, while nine (75%) pregnant women with fetuses with pathogenic CNVs chose to terminate the pregnancy. CONCLUSIONS: High-resolution SNP arrays are valuable tools for identifying submicroscopic chromosomal abnormalities in the prenatal diagnosis of VSDs. An excellent outcome can be expected for VSD fetuses that are negative for chromosomal anomalies and other severe anatomic abnormalities.

[Application of chromosome microarray analysis in 489 children with developmental delay/intellectual disability].

OBJECTIVE: To assess the value of chromosome microarray analysis (CMA) for identifying the etiology of developmental delay/intellectual disability (DD/ID). METHODS: A total of 489 children referred for DD/ID with or without other abnormalities were recruited. All patients showed a normal karyotype. DNA was extracted and hybridized with Affymetrix CytoScan 750K array by following the manufacturer's protocol. The data was analyzed with CHAS v2.0 software. RESULTS: The children were classified as with isolated DD/ID (n=358), DD/ID with epilepsy (n=49), and DD/ID with other structural anomalies (n=82). Pathogenic copy number variants (CNVs) were identified in 126 cases (25.8%), which included 89 (24.9%, 89/358) of whose with isolated DD/ID, 13 (26.5%, 13/49) of those with DD/ID and epilepsy, and 24 (29.3%, 24/82) of whose with DD/ID and other structural anomalies [P=0.064 (24.9% vs. 26.5%), P=0.679 (24.9% vs. 29.3%), and P=0.113 (26.5% vs. 29.3%), respectively]. Among the 126 cases, 79 were identified as microdeletion/microduplication syndromes, which included 15q24 microdeletion syndrome, Xq28 microduplication syndrome, and Lowe syndrome. Forty-seven cases had de novo pathogenic CNVs. ABAT, PMM2, FTSJ1, DYNC1H1 and SETBP1 were considered as candidate genes for DD/ID. CONCLUSION: CMA is an effective method for identifying the etiology of DD/ID and is capable of identifying microdeletion/microduplication syndromes as well as de novo pathogenic CNVs which may be missed by conventional karyotyping. Based on the results, candidate genes for DD/ID may be identified.

[Application of chromosome microarray analysis for the delineation of pathogenesis for fetal ventriculomegaly].

OBJECTIVE: To assess the value of genome-wide high-resolution chromosomal microarray analysis (CMA) for the delineation of pathogenesis for fetal ventriculomegaly diagnosed by ultrasound or magnetic resonance imaging (MRI). METHODS: Three hundred and forty-one cases of fetal ventriculomegaly were collected. The samples were grouped based on the extent of lateral ventricular dilatation, presence of additional features, site of occurrence, and the maternal age. All samples were subjected to karyotyping analysis. For those with a normal karyotype, DNA was extracted and hybridized with an Affymetrix CytoScan HD array. All cases were followed up. RESULTS: Among the 341 fetuses, 21 (6.2%) were detected with an abnormal karyotype. For the 320 cases with a normal karyotype, 179 (55.9%) have accepted CMA analysis. Potentially pathogenic CNVs were identified in 12 (6.7%) of the 179 cases, whose sizes ranged from 198 kb to 8.71 Mb. These included a 1q21.3q23.1 deletion, a 2q37.3 deletion, a 3p14.1p13 deletion, a 6q25.3 deletion, a 8q11.23 duplication, a 10q21.1 deletion, a 15q11.2 deletion and a 16p13.11p12.3 duplication, a 22q13.33 duplication, a 22q11.21 duplication and a Xp21.1 duplication (Duchenne muscular dystrophy). Pathogenic CNVs were detected respectively in 7.5% and 3.1% of those with mild and severe ventriculomegaly (P=0.615), in 6.1% and 7.4% of those with isolated and non-isolated ventriculomegaly (P=0.732), in 5.6% and 7.9% of those with unilateral and bilateral ventriculomegaly (P=0.511), and in 6.7% of both elderly and non-elderly groups (P=1.000). CONCLUSION: The detection rate for abnormal karyotypes among fetuses with ventriculomegaly was 6.2%. CMA can increase the detection rate by approximately 6.7%. There was no significant correlation between ventriculomegaly and presence of pathogenic CNVs. In clinical practice, fetuses with ventriculomegaly and a normal karyotype should be considered for CMA analysis.

[Application of chromosomal microarray analysis for fetuses with ventricular septal defects].

OBJECTIVE: To explore the genetic etiology of fetuses with ventricular septal defects (VSD) using chromosomal microarray analysis (CMA). METHODS: A total of 248 fetuses were divided into isolated VSD group, VSD with other cardiac and/or great vessels malformation group, VSD with extra-cardiac anomalies group (including malformation and sonographic soft markers), and VSD with both cardiac and extra-cardiac anomalies group. Standard karyotyping was carried out for all fetuses, and CMA was performed for 6 fetuses with an abnormal karyotype and a proportion of fetuses with a normal karyotype. All cases were followed up, and neonates were followed up until 1 year of age. RESULTS: Chromosomal abnormalities were identified in 60 (24.2%) of the 248 fetuses. For 6 of the fetuses subjected to further CMA analysis, the origin of abnormal chromosomes were clarified, among which 2 have overlapped with the critical region of Wolf-Hirschhorn syndrome. Candidate genes for VSD included WHSC1, LBX1, LDB3 and BBS10. For 143 fetuses with a normal karyotype, CMA has identified pathogenic copy number variations (CNVs) in 11 cases (7.7%). These included 9 well-known microdeletion or microduplication syndromes, including 22q11.2 microdeletion, 17p11.2 microdeletion (Smith-Magenis syndrome), 17p13.3 microdeletion (Miller-Dieker syndrome), 1p36 microdeletion, 1q21.1 microduplication and 4q deletion. Candidate genes for VSD included TBX1, LZTR1, FAT1, AKAP10, SKI, PRDM26, GJA5, ERCC4 and YWHAE. For 48.7% of the fetuses with benign CNVs, spontaneously closure has occurred within the first year of life. CONCLUSION: CMA may increase the detection rate of submicroscopic imbalances by 7.7%. No significant correlation between different groups of VSD and the pathogenic CNVs was observed. Whole-genome CMA should be recommended to the fetuses with VSD but a normal karyotype. Nearly half of VSDs with benign CNVs may close spontaneously within the first year of life.

Dent Disease in Chinese Children and Findings from Heterozygous Mothers: Phenotypic Heterogeneity, Fetal Growth, and 10 Novel Mutations.

OBJECTIVE: To characterize the phenotypes of Dent disease in Chinese children and their heterozygous mothers and to establish genetic diagnoses. STUDY DESIGN: Using a modified protocol, we screened 1288 individuals with proteinuria. A diagnosis of Dent disease was established in 19 boys from 16 families by the presence of loss of function/deleterious mutations in CLCN5 or OCRL1. We also analyzed 16 available patients' mothers and examined their pregnancy records. RESULTS: We detected 14 loss of function/deleterious mutations of CLCN5 in 15 boys and 2 mutations of OCRL1 in 4 boys. Of the patients, 16 of 19 had been wrongly diagnosed with other diseases and 11 of 19 had incorrect or unnecessary treatment. None of the patients, but 6 of 14 mothers, had nephrocalcinosis or nephrolithiasis at diagnosis. Of the patients, 8 of 14 with Dent disease 1 were large for gestational age (>90th percentile); 8 of 15 (53.3%) had rickets. We also present predicted structural changes for 4 mutant proteins. CONCLUSIONS: Pediatric Dent disease often is misdiagnosed; genetic testing achieves a correct diagnosis. Nephrocalcinosis or nephrolithiasis may not be sensitive diagnostic criteria. We identified 10 novel mutations in CLCN5 and OCRL1. The possibility that altered CLCN5 function could affect fetal growth and a possible link between a high rate of rickets and low calcium intake are discussed.