β-Thalassemia is a single-gene disease caused by mutations in β-globin and has a distinct geographical characteristics. Current treatment for patients with moderate to severe thalassemia has mainly relied on long-term blood transfusion and/or hematopoietic stem cell transplantation. B cell lymphoma/leukemia 11A (BCL11A) as a transcriptional repressor plays a vital role in monitoring γ/β hemoglobin switching, maintaining the normal function of hematopoietic stem cells, and regulating erythrocyte differentiation and lymphocyte development. With the rapid progress in gene editing technology, the BCL11A as a therapeutic target for β-thalassemia has shown promising results. This article has systematically summarized the regulatory mechanism and therapeutic potential of the BCL11A, with an aim to provide new ideas for the treatment of β-thalassemia.

Objective:To explore chromosomal copy number variations (CNVs) and pregnancy outcomes in fetuses with mild to moderate isolated ventriculomegaly (IVM), but without other indications for invasive prenatal diagnosis.Methods:A retrospective analysis was conducted on clinical data of 215 singleton pregnancies with mild to moderate IVM (lateral ventricular width≥10-<15 mm) who underwent chromosomal microarray analysis (CMA), not indicated by advanced age, high risk in serum screening or abnormal history of pregnancy, at the Fujian Maternity and Child Health Hospital between June 2016 and March 2023. The 215 fetuses were grouped into mild ( n=167) and moderate ( n=48) IVM;unilateral ( n=142) and bilateral ( n=73) IVM; first diagnosis of IVM before 28 weeks ( n=138) and thereafter ( n=77). Anomalies other than IVM were excluded via three-dimensional color Doppler ultrasound examination between 22 and 26 weeks of gestation. Out of these cases, 129 were confirmed by fetal cranial MRI, 191 underwent chromosomal karyotype analysis, and 202 cases received cytomegalovirus DNA quantification test for amniotic fluid. The detection rates of pathogenic CNVs in various groups were compared using Fisher's exact test. Results:Among the 215 fetuses, 11 cases (5.1%) of chromosomal abnormalities were detected through CMA, including one trisomy 21, five pathogenic CNVs, and five CNVs of uncertain clinical significance. Within the pathogenic CNVs, there were two de novo mutations with 16p11.2 microdeletion and one de novo mutation with 16p11.2 microduplication, while one 16p11.2 microduplication and one Xp22.31 microdeletion were inherited maternally. Of the CNVs of uncertain significance, there were two 16p13.11 microduplications, each inherited from a different parent, one paternally and one maternally; meanwhile, family validation was refused in the other three cases with 3p22.1 microdeletion, 3p26.3 microdeletion, and 9q21.33q22.31 microduplication. The detection rate of pathogenic CNVs in the moderate IVM group was higher than that in the mild IVM group [6.3% (3/48) vs. 1.2% (2/167)], but the difference was not statistically significant ( P=0.083). Similarly, no significant difference was found in the detection rate of pathogenic CNVs when comparing the unilateral IVM group [2.1% (3/142)] with the bilateral IVM group [2.7% (2/73)], nor between the group diagnosed with VM before 28 weeks gestation [2.2% (3/138)] and that diagnosed ≥28 weeks [2.6% (2/77)] (both P>0.05). After the exclusion of fetuses with chromosomal pathogenic abnormalities ( n=11), cytomegalovirus infection( n=1), and additional ultrasound anomalies ( n=7), and several cases with missing data intrauterine outcomes were followed up in 169 IVM fetuses, including 104 (61.5%) improved, 60 (35.5%) unchanged, and five (3.0%) progressed. Follow-ups were successful for 194 women, of which eight pregnancies were terminated (including one trisomy 21, four pathogenic CNVs, one fetal cytomegalovirus infection, and two progressed to severe IVM). Among the 186 newborns, one was diagnosed with X-linked ichthyosis, and one child who progressed to severe IVM before born was followed until 20 months of age without notable phenotypic abnormalities. The rest 184 babies, including those with CNVs of uncertain clinical significance, exhibited no developmental abnormalities during follow-up between the ages of three months and six years. Conclusions:For those fetuses with isolated mild to moderate IVM, but without indications for prenatal diagnosis such as advanced maternal age, high risk in serum screening or abnormal history of pregnancy, remain having the risk for chromosomal aberrations, and 16p11.2 microdeletion/microduplication might be a frequent CNV associated with this condition. Aside from those with pathogenic chromosomal aberrations, fetal cytomegalovirus infection, or progressive enlargement of the lateral ventricles, most fetuses with isolated mild to moderate IVM have a good prognosis.

This article reported the genetic analysis of a case diagnosed with fetal micrognathia and cleft palate by mid-trimester ultrasound in two consecutive pregnancies. In the first pregnancy, the pregnant woman delivered a full-term boy transvaginally, who died two weeks after birth and was diagnosed with Pierre Robin sequence (PRS). Chromosome karyotype and genomic copy number variation. In the second pregnancy, the woman underwent amniocentesis due to suspected PRS presenting by fetal cleft palate, micrognathism, and additional ultrasound anomalies. No abnormalities were detected in fetal karyotype or genomic copy number variation. Whole-exome sequencing, bioinformatics analysis, and Sanger sequencing suggested that both the fetus and the firstborn boy inherited a possible pathogenic variant of c.79delG p.E27Sfs*24 in the BMP2 gene from the mother. The pregnancy was terminated after the genetic consultation. Fetal phenotypes in the two fetuses were similar, indicating that short stature, facial dysmorphism, and skeletal anomalies with or without cardiac anomaly in the pedigree were caused by the heterozygous variant of c.79delG p.E27Sfs*24 in the BMP2 gene.

Objective:To investigate the clinical value of isolated fetal echogenic bowel (FEB) as an indicator for invasive prenatal diagnosis.Methods:This retrospective study enrolled 183 pregnant women who were diagnosed with isolated FEB and underwent invasive prenatal diagnosis in Fujian Maternity and Child Health Hospital from August 2013 to January 2021. Clinical data including the results of conventional karyotyping and chromosomal microarray analysis (CMA), cytomegalovirus (CMV) DNA loads in amniotic fluid and pregnancy outcomes were reviewed analyzed. Chi-square test was used for statistical analysis Results:Karyotyping was performed on all of the 183 fetuses and three (1.64%) aneuploidies (one case of trisomy 21, one trisomy 18 and one 47,XYY syndrome) were detected. One trisomy 21 and four pathogenic (P)/likely pathogenic (LP) copy number variation (CNV) were detected among 108 fetuses who received CMA. The detection rate of P/LP chromosomal abnormalities by CMA was higher than that by karyotyping, but there was no significant difference between them [4.63% (5/108) vs 0.93% (1/108), χ 2=1.54, P>0.05]. In addition, three cases of variants of uncertain significance (VOUS) were detected by CMA. CMV DNA loads of fetal cells in the amniotic fluid samples of the 166 cases were determined, and only one (0.6%) was positive (CMV DNA up to 7.01×10 6 copies/ml), and no abnormalities were found in karyotype analysis and CMA detection. A total of 176 cases were followed up, and among them only one case of intrauterine infection and seven cases (three aneuploidies and four P/LP CNV) of chromosomal abnormalities were terminated after genetic counseling. Three fetuses with VOUS and other 165 fetuses without chromosomal abnormalities had a good prognosis after birth. Conclusions:Isolated FEB may be the abnormal ultrasound finding in fetuses with chromosomal abnormalities or CMV infection. Prenatal genetic testing and the exclusion of intrauterine infection are important for management during pregnancy and prognosis assessment of FEB.

OBJECTIVE: To assess the application value of combined detection of HbA2 and HbF for the screening of thalassemia among a population of childbearing age in Quanzhou, Fujian, and determine the optimal cut-off values for the region. METHODS: Capillary hemoglobin electrophoresis and genetic testing for α and β globin gene mutations were simultaneously carried out on 11 428 patients with suspected thalassemia. Statistical methods were used to analyze the distribution of various types of thalassemia and compare the performance of HbA2 and HbF measurement for the screening of various types of thalassemia. The optimal cut-off values for HbA2 and HbF were determined with the ROC curves. RESULTS: 4591 patients with α, β, and αβ compound thalassemia were identified by genetic testing. The most common genotypes for α and β thalassemia included --SEA/αα and β654/βN, β41-42/βN, and β17/βN. The ROC curves were drawn to compare the performance of HbA2 screening for α-, β-, αβ-compound, static α-, mild α-, and intermediate α-thalassemia, and the maximum area under the curves was 0.674, 0.984, 0.936, 0.499, 0.731, 0.956, and the optimal cut-off values for HbA2 were 2.45%, 3.25%, 3.65%, 2.95%, 2.55%, 1.75%, respectively. CONCLUSION HbA2 is an efficient indicator for identifying intermediate types of α-, β-, and αβ compound thalassemia. The combination of HbA2 and HbF measurement can effectively detect carriers for β-thalassemia mutations.
Genotype ; Hemoglobin A2/genetics* ; Heterozygote ; Humans ; Mass Screening ; Mutation ; alpha-Thalassemia ; beta-Thalassemia/genetics*

OBJECTIVE: To analyze the intrauterine phenotype and genotype of eight fetuses carrying a 16p11.2 microdeletion. METHODS: 5100 fetuses undergoing routine prenatal diagnosis were subjected to single nucleotide polymorphism-based microarray (SNP-array) analysis. Fetuses harboring a 16p11.2 microdeletion were analyzed for their ultrasonographic characteristics. RESULTS: Eight fetuses were found to harbor a microdeletion in the 16p11.2 region. Among these, six had a typical 500-600 kb deletion, while the remaining two had an atypical 220 kb deletion at the distal part of 16p11.2. Four fetuses showed vertebral malformations, two had mild left ventriculomegaly, one had hydrocephalus, and one had pulmonary valve stenosis with regurgitation. The parents of five fetuses have accepted pedigree verification, and the results confirmed that the 16p11.2 microdeletions carried by fetuses all had a de novo origin. CONCLUSION The intrauterine phenotypes of fetuses carrying a 16p11.2 microdeletion may be variable, and the deletion can be effectively detected with the SNP-array assay.
Chromosome Deletion ; Female ; Fetus ; Genetic Testing ; Humans ; Phenotype ; Pregnancy ; Prenatal Diagnosis

β-thalassemia (β-thal) is one of the most common genetic diseases in the world, its pathogenesis is extremely complex and there is no effective treatment at present. The birth of children with moderate and severe β-thal brings economic pressure to families, social medical and health services. Long noncoding RNA (lncRNA) is a type of noncoding protein transcripts with a length greater than 200 nucleotides, which is involved in a variety of biological processes, such as cell proliferation, differentiation and chromosome variation and plays an important role in the epigenetic and post-transcriptional regulation of genes. It has potential value in the diagnosis, prevention and treatment of β-thal. LncRNA possesses the characteristics such as tissue specificity, cell specificity, developmental stage specificity, space-time specificity and disease specificity, and its complex interaction network has become a challenge to translate research results into clinical practice. Taking lncRNA as an entry point, in-depth understanding of the function of lncRNA in β-thal and explanation of its related regulatory mechanisms will provide theoretical basis for targeting treatment of β-thal, which can improve the diagnosis and treatment of β-thal.
Cell Differentiation ; Child ; Gene Expression Regulation ; Humans ; RNA, Long Noncoding/genetics* ; beta-Thalassemia/therapy*

OBJECTIVE: To analyze the ultrasonographic phenotype and result of genetic testing in six fetuses carrying a 17q12 microdeletion. METHODS: Chromosomal microarray analysis (CMA) was carried out for 6200 pregnant women undergoing prenatal diagnosis from December 2016 to May 2021. RESULTS: CMA has identified 6 fetuses with a microdeletion in the 17q12 region, which spanned approximately 1.4 Mb and encompassed at least 13 OMIM genes. All fetuses have shown bilateral renal parenchymal echo enhancement. Four fetuses also had other ultrasonographic phenotypes. The parents of 4 fetuses had refused parental verification, whilst the remaining two fetuses were confirmed to be de novo in origin. CONCLUSION The prenatal ultrasonographic phenotype of 17q12 microdeletion is mainly enhanced bilateral renal parenchymal echos. CMA can facilitate detection of the 17q12 microdeletion.
Female ; Humans ; Pregnancy ; Genetic Testing ; Phenotype ; Fetus/diagnostic imaging* ; Prenatal Diagnosis ; Parents

OBJECTIVE: To assess the value of copy number variations (CNVs) and chromosomal karyotyping analysis for patients with intellectual disability/developmental delay (ID/DD). METHODS: Chromosomal karyotype analysis was applied to 530 children diagnosed with ID/DD. Single nucleotide polymorphism array (SNP-array) was further applied for 120 children with unknown etiology. RESULTS: Among the 530 children with ID/DD, 104 (19.62%) were detected with chromosomal abnormalities. For the 120 children analyzed by SNP-array, 44 (36.67%) were detected with CNVs, among which 20 were predicted as pathogenic, 6 as likely pathogenic, 10 as variants of unknown significance, 7 as likely benign,and 1 as loss of heterozygosity. CONCLUSION SNP-array can facilitate delineation of the etiology of patients with ID/DD, which may provide a basis for their prognosis, consultation and clinical intervention.
Child ; Chromosome Aberrations ; DNA Copy Number Variations ; Developmental Disabilities/genetics* ; Humans ; Intellectual Disability/genetics* ; Karyotyping

OBJECTIVE: To evaluate the efficacy of non-invasive prenatal screening (NIPS) for fetal sex chromosome anomalies. METHODS: A retrospective analysis was carried out for 20 802 women undergoing NIPS screening. For 165 cases suspected for fetal sex chromosomal anomalies, the results of invasive prenatal diagnosis were obtained. RESULTS: Among the 165 cases suspected for fetal sex chromosome anomalies, 129 have accepted invasive prenatal diagnosis, and 45 were confirmed, which yielded a positive predictive value of 34.88%. These included 16 cases of 47,XYY, 10 cases of 47,XXY, 6 cases of 45,X/46,XX, 5 cases of 47,XXX, 3 cases of 45,X, 1 case of 45,X/46,X,i(X)(q10), 1 case of 45,X/46,X,del(X)(q22), 1 case of 46,X,del(X)(q22), 1 case of 46,X,del(X)(p11) and 1 case of Xp22.31 1.2 Mb deletion. CONCLUSION NIPS has limited value for detecting fetal sex chromosome anomalies. Karyotyping analysis combined with other diagnostic techniques can offer effective prenatal diagnosis for suspected cases.
Aneuploidy ; Female ; Humans ; Pregnancy ; Prenatal Diagnosis ; Retrospective Studies ; Sex Chromosomes/genetics* ; Trisomy