Routine antenatal molecular testing for α-thalassemia at a tertiary referral hospital in China: ten years of experience.

Objective: This study aimed to evaluate the efficacy of α-thalassemia gene testing as a part of an antenatal intervention program over a 10-year period. Methods: All patients underwent α-thalassemia gene testing, which included the analysis of three types of deletions and mutations. Rare α-thalassemia gene testing was performed using Sanger sequencing, multiplex ligation-dependent probe amplification, and sequencing techniques. Prenatal diagnosis was performed in high-risk couples using chorionic villus sampling or amniocentesis. Results: From 2010 to 2019, among the 91,852 patients examined, α-thalassemia mutations were identified in 41.78% of patients. The most frequent α0 gene mutation was--SEA, followed by--THAI. Two rare α0-thalassemia gene mutations at --32.8 and --230, were also observed. A total of 2,235 high-risk couples were identified, of which 562 were affected, including three with the--SEA/--THAI genotype and one with the--SEA/--230 genotype. Additionally, prenatal diagnosis revealed four cases of fetal anemia and/or mild edema, along with two cases of severe fetal edema. Chromosome and gene chip results were normal. Thalassemia gene testing showed an αCSα/αCSα genotype in four patients with anemia and/or mild edema, while two patients with severe fetal edema had one--SEA/αCSα genotype and one--SEA/--GX genotype. Using the cut-off points of 74.6 fL and 24.4 pg as criteria for identifying α0-thalassemia carriers and HbH disease, the detection rate of missed diagnoses in high-risk couples is consistent with national guidelines for standards, potentially saving 10,217,700 ¥. Conclusion: Routine molecular testing for α-thalassemia in high-risk prenatal populations effectively prevented severe α-thalassemia births. Despite the high cost, the cutoff points proposed by this study suggest that implementing screening using a new parameter has the potential to reduce current expenses.

Malformations of cortical development: Fetal imaging and genetics.

BACKGROUND: Malformations of cortical development (MCD) are a group of congenital disorders characterized by structural abnormalities in the brain cortex. The clinical manifestations include refractory epilepsy, mental retardation, and cognitive impairment. Genetic factors play a key role in the etiology of MCD. Currently, there is no curative treatment for MCD. Phenotypes such as epilepsy and cerebral palsy cannot be observed in the fetus. Therefore, the diagnosis of MCD is typically based on fetal brain magnetic resonance imaging (MRI), ultrasound, or genetic testing. The recent advances in neuroimaging have enabled the in-utero diagnosis of MCD using fetal ultrasound or MRI. METHODS: The present study retrospectively reviewed 32 cases of fetal MCD diagnosed by ultrasound or MRI. Then, the chromosome karyotype analysis, single nucleotide polymorphism array or copy number variation sequencing, and whole-exome sequencing (WES) findings were presented. RESULTS: Pathogenic copy number variants (CNVs) or single-nucleotide variants (SNVs) were detected in 22 fetuses (three pathogenic CNVs [9.4%, 3/32] and 19 SNVs [59.4%, 19/32]), corresponding to a total detection rate of 68.8% (22/32). CONCLUSION: The results suggest that genetic testing, especially WES, should be performed for fetal MCD, in order to evaluate the outcomes and prognosis, and predict the risk of recurrence in future pregnancies.

Compound variants of FKTN, POMGNT1, and LAMB1 gene identified by prenatal whole-exome sequencing in three fetuses with congenital hydrocephalus.

Congenital hydrocephalus (CH) is a severe birth defect, and genetics components is an important etiology. Whole-exome sequencing (WES) has been proven to be a feasible approach for prenatal diagnosis of CH. In this study, we carried out WES on three fetuses with cerebral ventriculomegaly. After bioinformation analysis and data filtering, three compound variants, c.919C>T(p.Arg307Ter)/c.1100del(p.Phe369fs) in FKTN, c.1449_1450insACAACG/c.1490G>C(p.Arg497Pro) in POMGNT1, and c.2690+1G>A/c.1447C>T(p.Arg483Cys) in LAMB1 were detected in the three fetuses. All the six variants were classified as likely pathogenic or pathogenic in accordance with the American College of Medical Genetics and Genomics-Association for Molecular Pathology guidelines. This study provides support for the potential of WES for the accurate prenatal diagnosis of fetal hydrocephalus and further demonstrated the genetic heterogeneity in patients with CH. The novel variants (c.1449_1450insACAACG and c.1490G>C in POMGNT1, c.2690+1G>A in LAMB1) expanded the gene mutational spectrum of CH and contributes to genetics counseling and pregnancy management.

Etiology and Outcome of non-immune Hydrops Fetalis in Southern China: report of 1004 cases.

Non-immune hydrops fetalis (NIHF) is a complex condition with a high mortality and morbidity rate. Here we report the etiology and outcome of 1004 fetuses with NIHF, in a large single Maternal and Children's hospital of Southern China, since the year of 2009 to 2016. Among these 1004 fetuses with NIHF, the etiology was identified prenatally in 722 of them (72%). The most common ones were hematologic diseases and chromosomal abnormalities. There were eight spontaneous abortions, 18 intrauterine fetal demise, 672 pregnancy terminations and 87 were lost to follow-up. 219 of the 1004 fetuses were live-born and the overall survival rate was 21.8% at this point. After birth 16 perinatal or early neonatal deaths were encountered and five lost to follow-up. Of the remaining 198 newborns, 153 thrived without apparent morbidity. The most significant factors associated with mortality were prematurity and low birthweight. In conclusion, we described the largest report of underlying causes and outcome of NIHF in Southern China. Etiologies were identified for 72% of 1004 fetuses with NIHF. And two poor prognostic factors for survival are preterm birth at less than 36.5 weeks and birthweight lower than 2575 g respectively.

Genetic Testing and Pregnancy Outcome Analysis of 362 Fetuses with Congenital Heart Disease Identified by Prenatal Ultrasound / Análise de Teste Genético e de Desfecho da Gestação de 362 Fetos com Cardiopatia Congênita Identificados por Ultrassom Pré-Natal

Abstract Background: Congenital heart defects (CHD), as the most common congenital anomaly, have been reported to be associated with chromosomal abnormalities. Currently, patients with CHD are routinely offered karyotyping and chromosomal microarray (CMA) testing, but the genotype-phenotype relationship has not yet been fully established. Objective: To determine the type and frequency of chromosomal abnormalities in fetuses with CHD and to analyze pregnancy outcomes of fetuses with heart abnormalities caused by different genetic factors. Methods: A total of 362 cases of CHD were enrolled from 2009 to 2016. Detailed ultrasound and laboratory examinations, including karyotyping and CMA, were performed. Outcome was obtained from discharge summaries. Results: Of the 362 fetuses, 220 were found with an isolated CHD, and 142 had CHD with extracardiac anomaly. Among these 362 fetuses, 140 were identified with a genetic cause, including 111 cases with aneuploidy, 10 cases with abnormality of chromosomal structure by karyotyping and 19 cases with pathogenic or likely pathogenic copy-number variations (CNVs) by CMA. The detection rate is close to 38.7%. Only one (identified as trisomy 18 syndrome) in 140 positive cases resulted in perinatal death, with the others being induced. The remaining 222 cases had negative results for both genetic testing and of these cases, 56 resulted in induced labor, and 77 had natural childbirth or caesarean births. The pregnancy outcome of the remaining 89 cases was uncertain. Conclusions: Karyotyping and CMA are effective and accurate prenatal genetic techniques for identifying fetal chromosomal abnormalities associated with cardiac defects, and this can assist clinical doctors to perform appropriate genetic counselling with regard to the etiology and outcome of CHD.

Resumo Fundamento: As cardiopatias congênitas (CCs) são as anomalias congênitas mais comuns, e têm sido associadas a anormalidades cromossômicas. Atualmente, a cariotipagem e a análise cromossômica por microarray (CMA) são oferecidas rotineiramente aos pacientes, mas a relação genótipo-fenótipo ainda não foi totalmente estabelecida. Objetivo: Determinar o tipo e a frequência das anomalias cromossômicas em fetos com CC e analisar os desfechos da gestação de fetos com anormalidades cardíacas causadas por diferentes fatores genéticos. Métodos: No total, foram admitidos 362 casos de CC entre 2009 e 2016. Ultrassonografia e exames laboratoriais detalhados foram realizados, incluindo cariotipagem e CMA. O resultado foi obtido a partir das folhas de epicrise. Resultados: Dos 362 fetos, 220 apresentaram doença coronariana isolada e 142 apresentaram doença coronariana com anomalia extracardíaca. Entre esses 362 fetos, foram identificados 140 com causa genética, incluindo 111 casos com aneuploidia, 10 casos com anormalidade da estrutura cromossômica por cariotipagem e 19 casos com variações no número de cópias (CNVs) patogênicas ou provavelmente patogênicas por CMA. A taxa de detecção é de aproximadamente 38,7%. Apenas um (identificado como síndrome da trissomia do cromossomo 18) em 140 casos positivos resultou em morte perinatal, com as demais sendo induzidas. Os 222 casos restantes tiveram resultados negativos para ambos os testes genéticos e, destes, 56 resultaram em trabalho de parto induzido e 77 tiveram partos naturais ou cesarianas. O desfecho da gravidez dos 89 casos restantes foi incerto. Conclusões: A cariotipagem e a CMA são técnicas genéticas pré-natais eficazes e precisas para a identificação de anomalias cromossômicas fetais associadas a defeitos cardíacos, e isso pode ajudar os médicos a realizar aconselhamento genético adequado com relação à etiologia e ao desfecho das cardiopatias congênitas.

Genetic Testing and Pregnancy Outcome Analysis of 362 Fetuses with Congenital Heart Disease Identified by Prenatal Ultrasound.

BACKGROUND: Congenital heart defects (CHD), as the most common congenital anomaly, have been reported to be associated with chromosomal abnormalities. Currently, patients with CHD are routinely offered karyotyping and chromosomal microarray (CMA) testing, but the genotype-phenotype relationship has not yet been fully established. OBJECTIVE: To determine the type and frequency of chromosomal abnormalities in fetuses with CHD and to analyze pregnancy outcomes of fetuses with heart abnormalities caused by different genetic factors. METHODS: A total of 362 cases of CHD were enrolled from 2009 to 2016. Detailed ultrasound and laboratory examinations, including karyotyping and CMA, were performed. Outcome was obtained from discharge summaries. RESULTS: Of the 362 fetuses, 220 were found with an isolated CHD, and 142 had CHD with extracardiac anomaly. Among these 362 fetuses, 140 were identified with a genetic cause, including 111 cases with aneuploidy, 10 cases with abnormality of chromosomal structure by karyotyping and 19 cases with pathogenic or likely pathogenic copy-number variations (CNVs) by CMA. The detection rate is close to 38.7%. Only one (identified as trisomy 18 syndrome) in 140 positive cases resulted in perinatal death, with the others being induced. The remaining 222 cases had negative results for both genetic testing and of these cases, 56 resulted in induced labor, and 77 had natural childbirth or caesarean births. The pregnancy outcome of the remaining 89 cases was uncertain. CONCLUSIONS: Karyotyping and CMA are effective and accurate prenatal genetic techniques for identifying fetal chromosomal abnormalities associated with cardiac defects, and this can assist clinical doctors to perform appropriate genetic counselling with regard to the etiology and outcome of CHD.

Etiology and Perinatal Outcome of Nonimmune Hydrops Fetalis in Southern China.

Objective This study aims to analyze the etiology and perinatal outcome of nonimmune hydrops fetalis (NIHF) in Southern China. Methods All cases with NIHF diagnosed antenatally from January 1, 2007 to December 31, 2014 were identified and analyzed. Results Total 482 cases of NIHF were identified during the study period. The most common cause of NIHF was hemoglobin (Hb) Bart's disease (61.8%), followed by chromosomal abnormalities (13.5%), idiopathic etiology (13.1%), cardiac abnormalities (6.4%), and others (5.2%). After 20 weeks' gestation, a total of 408 cases of NIHF presented, including Hb Bart's disease (279 cases), cardiac abnormalities (27 cases), and infection (7 cases). NIHF caused by chromosomal abnormalities mainly presented between 15 and 19 weeks' gestation. Of the 482 cases, 459 cases elected termination of pregnancy. The remaining 23 cases elected to continue their pregnancy. Among them, 14 (60.9%) resulted in intrauterine fetal death, 6 had neonatal death, 3 infants survived to 1 year of age. Of the three infants, one has cerebral palsy, and the remaining two are normal. Conclusions Hb Bart's disease is the most common cause of NIHF in Southern China. An effective prenatal screening and counseling program for thalassemia in this region may be the most effective way to lower the incidence NIHF.

Next-generation sequencing analysis of TSHR in 384 Chinese subclinical congenital hypothyroidism (CH) and CH patients.

BACKGROUND: Defects in the human TSHR gene are reported to be one of the causes of CH due to thyroid dysgenesis, the purpose of this study was to examine the TSHR mutation spectrum and prevalence in congenital hypothyroidism (CH) and subclinical congenital hypothyroidism (SCH) patients in the Guangxi Zhuang Autonomous Region of China and to evaluate the genotype-phenotype correlations. METHODS: Blood samples were collected from 384 patients including 240 CH and 144 SCH patients in Guangxi, China. Genomic DNA was extracted from peripheral blood leukocytes. All exons of the 11 known CH associated genes including TSHR together with their exon-intron boundaries were screened by next-generation sequencing (NGS). RESULTS: NGS analysis of TSHR revealed nine different variants in ten individuals. Six (4.2%) of 144 patients with SCH were found to harbor monoallelic TSHR variants. Four (1.6%) of 240 patients with CH harbored TSHR variants combined with another monoallelic mutation in either DUOX2 or TG gene. The present study identified five novel variants c.1838A>G (p.Y613C), c.1576G>A (p.A526T), c.2087T>G (p.F696C), c.1631G>A (p.G544E) and c.2051C>A (p.A684D) in TSHR, seven known pathogenic variants c.1349G>A (p.R450H), c.326G>A (p.R109Q), c.2066T>G (p.V689G) and c.2272G>A (p.E758K) in TSHR, IVS3+2T>G in TG, and c.1588A>T (p.K530X) and c.2635G>A (p.E879K) in DUOX2. The previously reported hotspot mutation p.R450H was found in only one SCH patient. CONCLUSION: The prevalence of TSHR mutations was 1.6% in CH patients and 4.2% in SCH patients in Guangxi Zhuang Autonomous Region of China. Monoallelic TSHR pathogenic variants were associated with SCH, while TSHR pathogenic variants combined with monoallelic mutations in DUOX2 or TG gene might contribute to CH. Our study expands the TSHR mutation spectrum and provides the best estimation of mutation rate for SCH and CH patients in this Chinese population.

Decreased endometrial vascularity and receptivity in unexplained recurrent miscarriage patients during midluteal and early pregnancy phases.

OBJECTIVE: To evaluate the predictive value of three-dimensional (3D)-power Doppler sonography on recurrent miscarriage. MATERIALS AND METHODS: The study patients were divided into a recurrent miscarriage group (30 cases) and a normal pregnancy group (21 cases). Measurement of endometrial thickness was performed using two-dimensional transvaginal ultrasound in the midluteal phase. The endometrial volume, vascularization index (VI), flow index (FI), and vascularization-flow index (VFI) in midluteal and placenta volume, as well as the VI, FI, and VFI of early pregnancy were measured using Virtual Organ Computer-aided Analysis of 3D-power Doppler ultrasound. RESULTS: Endometrial thickness, endometrial volume, endometrial vascular data, VI, FI, and VFI of the midluteal phase were lower in the recurrent miscarriage group compared with the normal pregnancy group (p < 0.05). Placental volume, VI, and VFI during early pregnancy were lower in the miscarriage group compared with the normal pregnancy group (p < 0.05). There was no significant change in FI between the recurrent miscarriage and control groups during early pregnancy (p > 0.05). The predictive accuracy of endometrial thickness, endometrial volume, VI, FI, and VFI in the midluteal phase, and placenta volume, VI, FI, and VFI in early pregnancy as measured by the receiver operating characteristic curve to predict miscarriage before 12 gestational weeks in participants was 0.681, 0.876, 0.770, 0.720, 0.879, 0.771, 0.907, 0.592, respectively. CONCLUSION: The 3D-power Doppler ultrasound is a more comprehensive and sensitive method for evaluating endometrial receptivity. Endometrial volume, VI, FI, and VFI in the midluteal phase, as well as VI in early pregnancy, can be considered as predictive factors for recurrent miscarriage.

Hb H Hydrops Fetalis Syndrome Caused by Association of the - -(SEA) Deletion and Hb Constant Spring (HBA2: c.427T > C) Mutation in a Chinese Family.

Hb Constant Spring (Hb CS; HBA2: c.427T > C) is an unstable hemoglobin (Hb) variant that results from a nucleotide substitution at the termination codon of the α2-globin gene. Compound heterozygosity for α(0)-thalassemia (α(0)-thal) and Hb CS (- -(SEA)/α(CS)α) results in Hb H/Hb CS disease, which is generally characterized with mild hemolytic anemia, jaundice, and splenomegaly. Here, we describe one case with Hb H/Hb CS disease that presented with fetal anemia and fetal hydrops, known as Hb H (ß4) hydrops fetalis. This is the first report of fetal hydrops caused by association of the - -(SEA) deletion and the α(CS)α mutation. Our study highlights the significance of watchful observation using a serial ultrasound method and care of pregnant women who have fetuses found to carry Hb H/Hb CS disease during pregnancy, to guard against the occurrence of fetal hydrops.

[Cytogenetic analysis of 105 new human abnormal karyotypes].

To analyze the genetic effect of the abnormal chromosome karyotype, we summarized and studied the clinical data of the new abnormal karyotypes diagnosed at the Guangxi Zhuang Autonomous Region Women and Children Care Hospital from January 2009 to July 2012. The samples were cultured routinely for the karyotype analysis using G banding and C banding. Chromosomal aberrations were named according to the International System for Human Cytogenetic Nomenclature (ISCN 2009). Among tested samples, 105 new human abnormal karyotypes were identified (86 reciprocal translocation, 10 chromosomal inversion, six derivative chromosome, one duplication, one isochromosome, one partial trisomy and monosomy). The results suggest that chromosomal abnormalities were a major cause of miscarriage, infertility, congenital abnormalities, mental retardation and amenorrhea in humans.

Detection of a novel large deletion causing α-thalassemia in South China.

α-Thalassemia is an inherited autosomal recessive disorder. It is one of the most common monogenic abnormalities known in the world and is prevalent in tropical and subtropical regions. α-Thalassemia is more frequently caused by deletional type than non-deletional type. Recently, we identified a novel large deletional type of α-thalassemia named --(FZ)/αα from a family in South China. Multiplex ligation-dependent probe amplification was used for diagnosing the carrier and prenatal diagnosing for a fetus. Real-time PCR was employed for characterizing the deletion breakpoints and the deletional segment was determined as 300 kb in length extending from the telomere to AXIN1 gene on the short arm of chromosome 16. The carriers in the family members were detected by real-time PCR using designed primers.

Three patients with Wolf-Hirschhorn syndrome carrying a satellited chromosome 4p.

BACKGROUND: Wolf-Hirschhorn syndrome (WHS) is caused by a deletion involving the 4p16.3 region. Approximately 70% of WHS patients have a de novo isolated deletion and 22% involve unbalanced translocations. However, WHS with unbalanced rearrangements involving the short arm of an acrocentric chromosome are infrequently reported. METHODS: Cytogenetic and molecular analyses by using standard G-banding, argyrophilic nucleolar organiser region (Ag-NOR) staining, fluorescence in situ hybridization, and single nucleotide polymorphism array for copy number detection were performed in three patients with WHS phenotype from two Chinese families. RESULTS: A heterozygous 2,767,380-bp terminal 4p deletion was detected in patients 1 and 2 and a heterozygous 5,047,291-bp terminal 4p deletion was detected in patient3. Clinical comparisons among our patients and previously reported cases have been reviewed. CONCLUSION: Two terminal 4p deletions were identified in three WHS patients with a satellited 4p and an attempt was made to refine the genotypic-phenotypic correlations of the deleted regions.

Tei index: the earliest detectable cardiac structural and functional abnormality detectable in Hb Bart's foetal edema.

OBJECTIVE: Premature death and still births are common in Hb Bart's foetal edema which carries significant risk to mothers. We aimed to identify early changes in cardiac structure and function in a cohort of HB Bart's foetuses, using Doppler echocardiography. METHODS: We studied 97 HB Bart's foetuses in different gestation groups; I (20-24 weeks),..., V (37-42 weeks) and compared them with age matched controls. We measured right and left atrial diameters as well as right and left ventricular diameters. From the Doppler filling and ejection velocities of the right and left ventricles we measured Tei index in 30 foetuses and compared them with age matched normal controls. RESULTS: The four cardiac chamber dimensions were not significantly different from the respective controls (p=NS for all). The right atrial diameter was enlarged in groups II, III, IV and V (p<0.05 vs normal controls). The right ventricle was significantly dilated in group III, IV and V (p<0.05-0.01) compared with normals. The left atrium and left ventricle were enlarged in groups III and IV, respectively (p<0.05 vs normals). Transmitral and transtricuspid E/A ratio was significantly less than normal in groups III (p<0.01), IV (p<0.05) and IV (p<0.05). LV and RV fractional shortening and stroke distance of group IV and V were significantly less than the respective normals (p<0.05 for all). LV and RV Tei index increased progressively from 20-week gestation (p<0.05) with respect to controls. CONCLUSIONS: In HB Bart's foetuses left and right ventricular asynchrony develop earlier than overt cavity dilatation and impairment of systolic function. The use of such markers of ventricular asynchronous function may play an important role in optimum management of these pregnancies.