Characterization of the Prenatal Ultrasound Phenotype Associated With 7q11.23 Microduplication Syndrome and Williams-Beuren Syndrome.

OBJECTIVE: This study aimed to characterize the intrauterine phenotype of fetuses with 7q11.23 microduplication syndrome and Williams-Beuren syndrome (WBS) to provide insight into prenatal genotype and phenotype correlations in the 7q11.23 region. METHODS: Seven fetuses with 7q11.23 microduplication syndrome and sixteen with WBS were diagnosed via array comparative genomic hybridization (array CGH) or copy number variation sequencing (CNV-seq) at our center. Clinical data were also systematically collected and analyzed, including intrauterine phenotype, pregnancy outcome, and inheritance. RESULTS: In our cases, the most common prenatal ultrasound feature of 7q11.23 microduplication syndrome was cardiovascular defects; less frequent features included choroid plexus cysts, anencephaly, bilateral pyelectasis, and cervical lymphatic hygroma. On the other hand, WBS was mainly associated with cardiovascular defects and intrauterine growth retardation. Other clinical phenotypes included hypoechoic frontal horn of the right lateral ventricle, crossed fused renal ectopia, hyperechogenic bowel, hyperechogenic right thoracic cavity, and hyperechogenic hepatic parenchyma/intrahepatic duct wall. CONCLUSIONS: Our study describes a series of new ultrasound features identified prenatally in fetuses with 7q11.23 microduplications and microdeletions with the intent of expanding the prenatal phenotype associated with copy number variants in this chromosomal region. Additional studies are needed to clearly delineate specific prenatal features associated with these rare genetic entities.

Clinical predictive value of pre-pregnancy tests for unexplained recurrent spontaneous abortion: a retrospective study.

Introduction: Early prediction and intervention are crucial for the prognosis of unexplained recurrent spontaneous abortion (uRSA). The main purpose of this study is to establish a risk prediction model for uRSA based on routine pre-pregnancy tests, in order to provide clinical physicians with indications of whether the patients are at high risk. Methods: This was a retrospective study conducted at the Prenatal Diagnosis Center of Henan Provincial People's Hospital between January 2019 and December 2022. Twelve routine pre-pregnancy tests and four basic personal information characteristics were collected. Pre-pregnancy tests include thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), free thyroxine thyroid (FT4), thyroxine (TT4), total triiodothyronine (TT3), peroxidase antibody (TPO-Ab), thyroid globulin antibody (TG-Ab), 25-hydroxyvitamin D [25-(OH) D], ferritin (Ferr), Homocysteine (Hcy), vitamin B12 (VitB12), folic acid (FA). Basic personal information characteristics include age, body mass index (BMI), smoking history and drinking history. Logistic regression analysis was used to establish a risk prediction model, and receiver operating characteristic (ROC) curve and decision curve analysis (DCA) were employed to evaluate the performance of prediction model. Results: A total of 140 patients in uRSA group and 152 women in the control group were randomly split into a training set (n = 186) and a testing set (n = 106). Chi-square test results for each single characteristic indicated that, FT3 (p = 0.018), FT4 (p = 0.048), 25-(OH) D (p = 0.013) and FA (p = 0.044) were closely related to RSA. TG-Ab and TPO-Ab were also important characteristics according to clinical experience, so we established a risk prediction model for RSA based on the above six characteristics using logistic regression analysis. The prediction accuracy of the model on the testing set was 74.53%, and the area under ROC curve was 0.710. DCA curve indicated that the model had good clinical value. Conclusion: Pre-pregnancy tests such as FT3, FT4, TG-Ab, 25-(OH)D and FA were closely related to uRSA. This study successfully established a risk prediction model for RSA based on routine pre-pregnancy tests.

Correlation between maternal serum biomarkers and the risk of fetal chromosome copy number variants: a single-center retrospective study.

OBJECTIVE: To explore the association between the concentration of maternal serum biomarkers and the risk of fetal carrying chromosome copy number variants (CNVs). METHODS: Pregnant women identified as high risk in the second-trimester serological triple screening and underwent traditional amniotic fluid karyotype analysis, along with comparative genomic hybridization array (aCGH)/copy number variation sequencing (CNV-seq), were included in the study. We divided the concentration of serum biomarkers, free beta-human chorionic gonadotropin (fß-hCG), alpha fetoprotein (AFP) and unconjugated estriol (uE3), into three levels: abnormally low, normal and abnormally high. The prevalence of abnormally low, normal and abnormally high serum fß-hCG, AFP and uE3 levels in pregnant women with aberrant aCGH/CNV-seq results and normal controls was calculated. RESULTS: Among the 2877 cases with high risk in the second-trimester serological triple screening, there were 98 chromosome abnormalities revealed by karyotype analysis, while 209 abnormalities were detected by aCGH/CNVseq (P＜0.001) . The carrying rate of aberrant CNVs increased significantly when the maternal serum uE3 level was less than 0.4 multiple of median (MoM) of corresponding gestational weeks compared to normal controls, while the carrying rate of aberrant CNVs decreased significantly when the maternal serum fß-hCG level was greater than 2.5 MoM compared to normal controls. No significant difference was found in the AFP group. CONCLUSION: Low serum uE3 level (<0.4 MoM) was associated with an increased risk of aberrant CNVs.

Transcriptome research of human amniocytes identifies hub genes associated with developmental dysplasia in down syndrome.

Trisomy 21, or Down syndrome (DS), is the most frequent human autosomal chromosome aneuploidy, which leads to multiple developmental disorders, especially mental retardation in individuals. The presence of an additional human chromosome 21 (HSA21) could account for the pathological manifestations in DS. In this study, we analyzed the mRNA gene expression profile of DS-derived amniocytes compared with normal amniocytes, aiming to evaluate the relationship between candidate dysregulated HSA21 genes and DS developmental phenotypes. Differentially expressed genes (DEGs) included 1794 upregulated genes and 1411 downregulated genes, which are mainly involved in cell adhesion, inflammation, cell proliferation and thus may play an important role in inducing multiple dysplasia during DS fetal development. Furthermore, STRING protein network studies demonstrated 7 candidate HSA21 genes participated Gene Ontology (GO) terms: cell adhesion and extracellular matrix remodeling (COL6A1, COL6A2, COL18A1, ADAMTS5, JAM2, and POFUT2), inflammation and virus infection response (MX1 and MX2), histone modification and chromatin remodeling (NRIP1), glycerolipid and glycerophospholipid metabolism (AGPAT3), mitochondrial function (ATP5PF and ATP5PO), synaptic vesicle endocytosis (ITSN1 and SYNJ1) and amyloid metabolism (APP). Meanwhile, GSEA enrichment identified several transcription factors and miRNAs, which may target gene expression in the DS group. Our study established connections between dysregulated genes, especially HSA21 genes, and DS-associated phenotypes. The alteration of multiple pathways and biological processes may contribute to DS developmental disorders, providing potential pathogenesis and therapeutic targets for DS.

HNRNPC mediated m6A methylation of 5-methyltetrahydrofolate-homocysteine methyltransferase and involved in the occurrence of RSA.

N6-methyladenosine methylated modification has been shown to play roles in recurrent spontaneous abortion. We aimed to explore role of heterogeneous nuclear ribonucleoprotein C in the occurrence of recurrent spontaneous abortion. We collected embryonic villous tissues from 3 patients with recurrent spontaneous abortion (RSA group) and 3 normal control pregnancy patients. Methylated RNA immunoprecipitation sequencing, RNA sequencing, methylated RNA immunoprecipitation quantitative PCR were conducted to detect the differentially expressed m6A methylation modification gene and regulatory gene in patients with recurrent spontaneous abortion. Methylated RNA immunoprecipitation sequencing and RNA sequencing results showed that the mRNA expression level of heterogeneous nuclear ribonucleoprotein C significantly decreased in RSA group and mRNA expression level of 5-methyltetrahydrofolate-homocysteine methyltransferase increased. Real-time quantitative PCR confirmed the differential expression of heterogeneous nuclear ribonucleoprotein C and 5-methyltetrahydrofolate-homocysteine methyltransferase. Methylated RNA immunoprecipitation quantitative PCR result showed that mRNA m6A modification level of 5-methyltetrahydrofolate-homocysteine methyltransferase decreased in RSA group. The results of western blotting, real-time quantitative PCR, immunofluorescence, matrigel invasion and wound healing assays indicated that heterogeneous nuclear ribonucleoprotein C might regulate the expression of 5-methyltetrahydrofolate-homocysteine methyltransferase by mediating m6A modification, thereby reducing the proliferation and migration of trophoblast cell line, ultimately leading to the occurrence of recurrent spontaneous abortion.

Construction and evaluation of a novel set of 90 microhaplotypes for forensic applications using NGS technology.

Microhaplotypes (MHs), small sets of linked single nucleotide polymorphisms (SNPs), are becoming a valuable tool for paternity testing, personal identification and other different forensic purposes due to their advantages of both short tandem repeats (STRs) and SNPs. However, only a small part of MHs with small segments have been developed and reported so far. And the current population genetic data of MHs are still insufficient. MHs with small segments possess unique advantages in mixture deconvolution, degradation material identification, noninvasive prenatal paternity testing and even medical tumor diagnostic applications. In the present study, a set of 90 autosomal MHs whose PCR amplicon lengths are from 90-150 bp, of which 58 MHs are less than or equal to 100 bp are selected, and assembled into an amplification multiplex system optimized for Ion S5™ System for forensic application. Genetic diversity study of 90 MHs in the populations from different intercontinental regions shows that the polymorphism information content (PIC) values of 83 MHs are greater than 0.4 in populations from East Asia (EAS), and the average PIC value of 90 MHs is greater than 0.5. A total of EAS populations shows the highest cumulative match probability (CMP) and cumulative probability of exclusion (CPE) values in five intercontinental populations. The CMP and CPE values of 90 MHs in EAS are 1.1688 × 10-54 and 0.999999999998954. The informativeness for assignment (In) values of the 90 MHs are calculated based on data from five intercontinental populations, and the In values of 20 MHs have greater than 0.1, indicating that the 20 MHs are high effectiveness in distinguishing different intercontinental populations, which can be used as candidate ancestry informative markers. Further, we have studied the polymorphisms of the 90 MHs based on 224 unrelated individuals of Henan Han population, China, and obtained the frequency data of the 90 MHs. In the Henan Han population, the effective number of alleles (Ae) of the 90 MHs ranges from 1.7649 (MH45) to 3.9792 (MH50), and the Ae values of 10 MHs reach to 3.0; the Ae values of 80 MHs are greater than 2, and the average Ae value for these MHs is 2.422. The average expected heterozygosity, observed heterozygosity, PIC, matching probability, discrimination power and probability of exclusion values of 90 MHs in the Henan Han population are 0.5788, 0.5851, 0.5039, 0.2608, 0.7392 and 0.2806, respectively. The CMP value of 90 MHs in the study population is less than 10-54, and their CPE value reaches 0.999999999999999923. Moreover, the results of the depth of coverage, allele coverage ratio and noise level indicate that the 90 MH amplification system has well sequencing performance, and the sequencing results are reliable. The results indicate the 90 MHs show higher polymorphisms in the study population. The present panel can be well used in paternity testing and individual identification in the study population and even the populations from EAS.

Functional analysis of a novel nonsense variant c.91A>T of the TRAPPC2 gene in a Chinese family with X-linked recessive autosomal spondyloepiphyseal dysplasia tarda.

Spondyloepiphyseal dysplasia tarda (SEDT) is a condition involving late-onset, X-linked recessive skeletal dysplasia caused by mutations in the TRAPPC2 gene. In this paper, we identified a novel nonsense variant in a SEDT pedigree and analyzed the function of the variant in an attempt to explain the new pathogenesis of the TRAPPC2 protein in SEDT. Briefly, DNA and RNA samples from the peripheral blood of SEDT individuals were prepared. The causative variant in the Chinese SEDT family was identified by clinic whole-exome sequencing analysis. Then, we observed the mRNA expression of TRAPPC2 in patients and the mutant TRAPPC2 level in vitro and analyzed the protein stability and subcellular distribution by cell fluorescence and Western blotting. We also investigated the effect of TRAPPC2 knockdown on the expression and secretion of COL2A1 in SW1353 cells or primary human chondrocytes. Herein, we found a nonsense variant, c.91A>T, of the TRAPPC2 gene in the pedigree. TRAPPC2 mRNA expression levels were significantly decreased in the available peripheral blood cell samples of two affected patients. An in vitro study showed that the mutant plasmid exhibited significantly lower mRNA and protein of TRAPPC2, and the mutant protein changed its membrane distribution. TRAPPC2 knockdown resulted in decreased COL2A1 expression and collagen II secretions. Our data indicate that the novel nonsense variant, c.91A>T, of the TRAPPC2 gene is the cause of SEDT in this pedigree. The variant results in a lowered expression of TRAPPC2 and then affects the COL2A1 expression and collagen II secretions, which may explain the mechanism of loss of function of the variant.

Identification of a novel de novo mutation of SETBP1 and new findings of SETBP1 in tumorgenesis.

BACKGROUND: In the past decade, SETBP1 has attracted a lot of interest on that the same gene with different type or level (germline or somatic) of variants could provoke different pathologic consequences such as Schinzel-Giedon syndrome, SETBP1 Haploinsufficiency Disorder (SETBP1-HD) and myeloid malignancies. Whole exome sequencing was conducted to detect the etiology of a pregnant woman with mental retardation. As a new oncogene and potential marker of myeloid malignancies, somatic SETBP1 variants in other cancers were rarely studied. We performed a pan-cancer analysis of SETBP1 gene in different cancers for the first time. RESULTS: A novel heterozygous mutation of the SETBP1 gene (c.1724_1727del, p.D575Vfs*4) was found in the patient and the fetus and the mutation was predicted to result in a truncated protein. Reduced SETBP1 expression was associated with SETBP1-HD. The pan-cancer analysis of SETBP1 showed that SETBP1 overexpression should be given special attention in Bladder Urothelial Carcinoma (BLCA) and Stomach adenocarcinoma (STAD). CONCLUSIONS: The de novo SETBP1 mutation was the genetic cause of SETBP1-HD in the family. BLCA and STAD might be related to SETBP1 overexpression.

[Clinical features and genetic analysis of two Chinese pedigrees affected with Joubert syndrome].

OBJECTIVE: To explore the clinical characteristics and genetic basis of two Chinese pedigrees affected with Joubert syndrome. METHODS: Clinical data of the two pedigrees was collected. Genomic DNA was extracted from peripheral blood samples and subjected to high-throughput sequencing. Candidate variants were verified by Sanger sequencing. Prenatal diagnosis was carried out for a high-risk fetus from pedigree 2. RESULTS: The proband of pedigree 1 was a fetus at 23+5 weeks gestation, for which both ultrasound and MRI showed "cerebellar vermis malformation" and "molar tooth sign". No apparent abnormality was noted in the fetus after elected abortion. The fetus was found to harbor c.812+3G>T and c.1828G>C compound heterozygous variants of the INPP5E gene, which have been associated with Joubert syndrome type 1. The proband from pedigree 2 had growth retardation, mental deficiency, peculiar facial features, low muscle tone and postaxial polydactyly of right foot. MRI also revealed "cerebellar dysplasia" and "molar tooth sign". The proband was found to harbor c.485C>G and c.1878+1G>A compound heterozygous variants of the ARMC9 gene, which have been associated with Joubert syndrome type 30. Prenatal diagnosis found that the fetus only carried the c.485C>G variant. A healthy infant was born, and no anomalies was found during the follow-up. CONCLUSION: The compound heterozygous variants of the INPP5E and ARMC9 genes probably underlay the disease in the two pedigrees. Above finding has expanded the spectrum of pathogenic variants underlying Joubert syndrome and provided a basis for genetic counseling and prenatal diagnosis.

Nicotine Ingestion Reduces Heart Rate Variability in Young Healthy Adults.

Around the whole world, smoking is considered harmful to human health, such as increasing the risk of cardiovascular disease (CVD, such as coronary heart disease and stroke) and lung cancer. The purpose of this study was to explore whether nicotine, the main component of tobacco, has adverse effects on heart rate variability (HRV) in adolescents, so as to remind adolescents not to smoke and not to take pleasure in abusing nicotine. In this study, 40 male and 40 female young healthy nonsmoking subjects were selected to analyze the changes of HRV after taking 4 mg nicotine orally. We found that nicotine reduced HRV in young healthy male and female subjects, and there was no gender difference in this effect (P > 0.05). In conclusion, smoking is harmful to the cardiac system of young people, especially when nicotine content ≥4 mg dosage.

[Analysis of a Chinese pedigree affected with dyschromatosis symmetrica hereditaria due to a novel variant of ADAR gene].

OBJECTIVE: To explore the genetic basis for a Chinese pedigree affected with dyschromatosis symmetrica hereditaria (DSH). METHODS: PCR and Sanger sequencing were carried out for the proband, and suspected variant was validated by Sanger sequencing in the pedigree. RESULTS: The proband was found to harbor a novel variant of c.1352delA (p.N451Mfs*13) of the ADAR (NM_001111) gene. The same variant was found in her affected mother and sister, but not in her unaffected father, uncle, and 100 healthy individual. CONCLUSION: The novel variant of the ADAR gene probably underlay the pathogenesis of DSH in this pedigree.

A Novel Variant of the KIF11 Gene, c.2922G>T, Is Associated with Microcephaly by Affecting RNA Splicing.

Microcephaly with or without chorioretinopathy, lymphedema, or mental retardation (MCLMR) is an inherited disorder characterized by severe microcephaly and abnormal facial features. Kinesin family member 11 (KIF11) mutations have been reported closely related to microcephaly in different cases, while the pathogenicity was still unclear. Here, we report a de novo heterozygous mutation in exon 20 of the KIF11 (c.2922G>T; p.Pro974=) from a microcephaly patient through whole-exome sequencing. Further studies identified that this variant affected the normal splicing of KIF11 pre-mRNA, thus leading to the c.2815_2922 deletion of exon 20 through PBMC-derived pre-mRNA splicing assay and minigene experiment. Moreover, c.2815_2922 deletion would produce a shortened KIF11 protein, which may competitively bind to the normal KIF11 protein, suggesting a dominant negative effect mechanism in c.2922G>T mutation-induced MCLMR.

Phase separation of Epstein-Barr virus EBNA2 protein reorganizes chromatin topology for epigenetic regulation.

Epstein-Barr virus nuclear antigen 2 (EBNA2) is a transactivator of viral and cellular gene expression, which plays a critical role in the Epstein-Barr virus-associated diseases. It was reported that EBNA2 regulates gene expression by reorganizing chromatin and manipulating epigenetics. Recent studies showed that liquid-liquid phase separation plays an essential role in epigenetic and transcriptional regulation. Here we show that EBNA2 reorganized chromatin topology to form accessible chromatin domains (ACDs) of the host genome by phase separation. The N-terminal region of EBNA2, which is necessary for phase separation, is sufficient to induce ACDs. The C-terminal domain of EBNA2 promotes the acetylation of accessible chromatin regions by recruiting histone acetylase p300 to ACDs. According to these observations, we proposed a model of EBNA2 reorganizing chromatin topology for its acetylation through phase separation to explain the mechanism of EBNA2 hijacking the host genome by controlling its epigenetics.

Epicardium-Derived Tbx18+ CDCs Transplantation Improve Heart Function in Infarcted Mice.

Cardiosphere-derived cells (CDCs) constitute a cardiac stem cell pool, a promising therapeutics in treating myocardial infarction (MI). However, the cell source of CDCs remains unclear. In this study, we isolated CDCs directly from adult mouse heart epicardium named primary epicardium-derived CDCs (pECDCs), which showed a different expression profile compared with primary epicardial cells (pEpiCs). Interestingly, pECDCs highly expressed T-box transcription factor 18 (Tbx18) and showed multipotent differentiation ability in vitro. Human telomerase reverse transcriptase (hTERT) transduction could inhibit aging-induced pECDCs apoptosis and differentiation, thus keeping a better proliferation capacity. Furthermore, immortalized epicardium CDCs (iECDCs) transplantation extensively promote cardiogenesis in the infracted mouse heart. This study demonstrated epicardium-derived CDCs that may derive from Tbx18+ EpiCs, which possess the therapeutic potential to be applied to cardiac repair and regeneration and suggest a new kind of CDCs with identified origination that may be followed in the developing and injured heart.

Emerging Roles Of hsa-circ-0046600 Targeting The miR-640/HIF-1α Signalling Pathway In The Progression Of HCC.

PURPOSE: Circular RNAs (circRNAs) play important roles in the development and progression of various human cancers. hsa-circ-0046600 is a circRNA of unknown function. The purpose of this study was to investigate the biological function of hsa-circ-0046600 in hepatocellular carcinoma (HCC) and elucidate the possible molecular mechanisms of this circRNA. MATERIALS AND METHODS: GSE97332, quantitative reverse transcription polymerase chain reaction (qRT-PCR) and fluorescence in situ hybridization (FISH) were used to detect the expression of hsa-circ-0046600 in HCC tissues and cells. A dual-luciferase reporter assay was used to confirm the interaction between hsa-circ-0046600 and miR-640, and a meta-analysis confirmed the expression of miR-640 in HCC. Bioinformatics was used for the functional analysis of miR-640 target genes. N-cadherin and HIF-1α expression was measured by Western blot analysis. RESULTS: The expression level of hsa-circ-0046600 in HCC tissue was significantly higher than that in adjacent normal tissue (P < 0.05) and was associated with tumour size, TNM stage and pathological vascular invasion. Moreover, the downregulated expression of hsa-circ-0046600 significantly inhibited the migration of HepG2 and SK-HEP-1 cells. hsa-circ-0046600 is present mainly in the cytoplasm and promotes the expression of proteins such as HIF-1α by competitively binding to miR-640 in HCC, thereby affecting the malignant biological behaviour of liver cancer cells. CONCLUSION: hsa-circ-0046600 can be used as a new biomarker for HCC diagnosis and disease progression and provides a potential target for targeted therapy.

[Analysis of MYO7A gene mutation in a family with non-syndromic autosomal recessive deafness].

OBJECTIVE: To explore the genetic basis for a family with non-syndromic autosomal recessive deafness. METHODS: The proband and her parents were subjected to physical and audiological examinations. With genomic DNA extracted from peripheral blood samples, next-generation sequencing was carried out using a panel for deafness genes. Suspected mutation was validated by Sanger sequencing and qPCR analysis of her parents. RESULTS: The proband presented bilateral severe sensorineural hearing loss at three days after birth. Her auditory threshold was 110-120 dBnHL but with absence of vestibular and retinal symptoms. Her brother also had deafness but her parents were normal. No abnormality was found upon physical examination of her family members, while audiological examination showed no middle ear or retrocochlear diseases. Next-generation sequencing identified compound heterozygous mutations of the MYO7A gene, including a previously known c.462C>A (p. Cys154Ter) and a novel EX43_46 Del, which were respectively derived from her mother and father. CONCLUSION: The compound heterozygous mutations of the MYO7A gene probably underlie the disease in this family. Our findings has enriched the mutation spectrum for non-syndromic autosomal recessive deafness 2.

A dominant variant in the PDE1C gene is associated with nonsyndromic hearing loss.

Identification of genes with variants causing non-syndromic hearing loss (NSHL) is challenging due to genetic heterogeneity. The difficulty is compounded by technical limitations that in the past prevented comprehensive gene identification. Recent advances in technology, using targeted capture and next-generation sequencing (NGS), is changing the face of gene identification and making it possible to rapidly and cost-effectively sequence the whole human exome. Here, we characterize a five-generation Chinese family with progressive, postlingual autosomal dominant nonsyndromic hearing loss (ADNSHL). By combining population-specific mutation arrays, targeted deafness genes panel, whole exome sequencing (WES), we identified PDE1C (Phosphodiesterase 1C) c.958G>T (p.A320S) as the disease-associated variant. Structural modeling insights into p.A320S strongly suggest that the sequence alteration will likely affect the substrate-binding pocket of PDE1C. By whole-mount immunofluorescence on postnatal day 3 mouse cochlea, we show its expression in outer (OHC) and inner (IHC) hair cells cytosol co-localizing with Lamp-1 in lysosomes. Furthermore, we provide evidence that the variant alters the PDE1C hydrolytic activity for both cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP). Collectively, our findings indicate that the c.958G>T variant in PDE1C may disrupt the cross talk between cGMP-signaling and cAMP pathways in Ca2+ homeostasis.

[Analysis of WAS gene mutation in a Chinese family affected with Wiskott-Aldrich syndrome].

OBJECTIVE: To detect potential mutation of the WAS gene in a Chinese family affected with Wiskott-Aldrich syndrome. METHODS: Peripheral blood samples were collected from the proband and his family members. All exons and flanking regions of the WAS gene were subjected to PCR amplification - Sanger sequencing as well as restriction endonuclease analysis. Plasma level of B-cell activating factor (BAFF) was also determined for all family members. RESULTS: A hemizygous mutation (c.257G>A) of the WAS gene was identified in all patients from the family, for which the patient's mother was heterozygous. The same mutation was not found among healthy members of the family. Compared with unaffected members, all patients had a higher level of BAFF. CONCLUSION: The c.257G>A mutation of the WAS gene probably underlies the Wiskott-Aldrich syndrome in this family.

[Genetic analysis of a child with cleidocranial dysplasia and 6q21-q22.31 microdeletion].

OBJECTIVE: To carry out genetic analysis on a child with developmental delay and multiple malformation. METHODS: The karotypes of the child and her parents were analyzed with routine chromosomal G-banding. Their genomic DNA was analyzed with array comparative genomic hybridization (aCGH). RESULTS: The karyotype of the proband was determined as 46,XX,del(6)(q22),inv(6)(p21.1q21), while no karyotypic abnormality was detected in her parents. aCGH has identified in the child a de novo 800 kb deletion encompassing the RUNX2 gene at 6p21.1 and a de novo 11.79 Mb deletion at 6q21-q22.31. CONCLUSION: Both of the de novo deletions are pathogenic. Deletion of the RUNX2 gene probably underlies the cleidocranial dysplasia in the patient, while the 6q21-q22.31 deletion may result in malformation of the brain.

[Identification of a novel EXT1 mutation in a pedigree affected with hereditary multiple exostosis].

OBJECTIVE To detect potential mutations of the EXT1 and EXT2 genes in a pedigree affected with hereditary multiple exostosis (HME). METHODS For a four-generation family with 7 affected individuals from 17 family members,genomic DNA was extracted from peripheral venous blood samples. All exons of the EXT1 and EXT2 genes were screened for potential mutation by PCR and Sanger sequencing. RESULTS A novel heterozygous frameshift mutation c.1202delT (p.I401Tfs*2)was found in exon 4 of the EXT1 gene in the proband and the other 6 affected individuals. The same mutation was not detected among the healthy members from the family. The mutation has given rise a truncated EXT1 protein with loss of 345 amino acids. CONCLUSION A novel frameshift mutation of the EXT1 gene has been identified in a pedigree affected with HME, which has enriched the mutational spectrum of the EXT1 gene and may facilitate genetic counseling and prenatal diagnosis for the family.