ABSTRACT
Next-generation phenotyping (NGP) can be used to compute the similarity of dysmorphic patients to known syndromic diseases. So far, the technology has been evaluated in variant prioritization and classification, providing evidence for pathogenicity if the phenotype matched with other patients with a confirmed molecular diagnosis. In a Nigerian cohort of individuals with facial dysmorphism, we used the NGP tool GestaltMatcher to screen portraits prior to genetic testing and subjected individuals with high similarity scores to exome sequencing (ES). Here, we report on two individuals with global developmental delay, pulmonary artery stenosis, and genital and limb malformations for whom GestaltMatcher yielded Cornelia de Lange syndrome (CdLS) as the top hit. ES revealed a known pathogenic nonsense variant, NM_133433.4: c.598C>T; p.(Gln200*), as well as a novel frameshift variant c.7948dup; p.(Ile2650Asnfs*11) in NIPBL. Our results suggest that NGP can be used as a screening tool and thresholds could be defined for achieving high diagnostic yields in ES. Training the artificial intelligence (AI) with additional cases of the same ethnicity might further increase the positive predictive value of GestaltMatcher.
Subject(s)
De Lange Syndrome , Phenotype , Humans , De Lange Syndrome/genetics , De Lange Syndrome/diagnosis , De Lange Syndrome/pathology , Male , Female , Child , Nigeria , Child, Preschool , Cell Cycle Proteins/genetics , Exome Sequencing , Genetic Testing/methods , High-Throughput Nucleotide Sequencing , InfantABSTRACT
BACKGROUND: Cornelia de Lange syndrome (CdLS) is a multisystem genetic disorder, and cases caused by variants in the structural maintenance of chromosomes protein 3 (SMC3) gene are uncommon. Here, we report two cases of CdLS associated with novel pathogenic variants in SMC3 from two Chinese families. METHODS: Clinical presentations of two patients with CdLS were evaluated, and specimens from the patients and other family members were collected for Trio-based whole-exome sequencing. Pyrosequencing, chip-based digital PCR, minigene splicing assay, and in silico analysis were carried out to elucidate the impact of novel variants. RESULTS: Novel heterozygous variants in SMC3 were identified in each proband. One harbored a novel splicing and mosaic variant (c.2535+1G>A) in SMC3. The mutated allele G>A conversion was approximately 23.1% by digital PCR, which indicated that 46.2% of peripheral blood cells had this variant. Additionally, in vitro minigene splicing analysis validated that the c.2535+1G>A variant led to an exon skipping in messenger RNA splicing. The other carried a heterozygous variant (c.435C>A), which was predicted to be pathogenic as well as significantly altered in local electrical potential. The former showed multiple abnormalities and marked clinical severity, and the latter mainly exhibited a speech developmental disorder and slightly facial anomalies. CONCLUSION: Both patients were clinically diagnosed with Cornelia de Lange syndrome 3 (CdLS3). The newly identified SMC3 gene variants can expand the understanding of CdLS3 and provide reliable evidence for genetic counseling to the affected family.
Subject(s)
Cell Cycle Proteins , Chromosomal Proteins, Non-Histone , De Lange Syndrome , Female , Humans , Male , Cell Cycle Proteins/genetics , Chondroitin Sulfate Proteoglycans , Chromosomal Proteins, Non-Histone/genetics , De Lange Syndrome/genetics , De Lange Syndrome/pathology , Heterozygote , Mutation , Pedigree , Phenotype , RNA SplicingABSTRACT
SMC1A epilepsy syndrome or developmental and epileptic encephalopathy-85 with or without midline brain defects (DEE85, OMIM #301044) is an X-linked neurologic disorder associated with mutations of the SMC1A gene, which is also responsible for about 5% of patients affected by Cornelia de Lange syndrome spectrum (CdLS). Only described in female patients, SMC1A epilepsy syndrome is characterized by the onset of severe refractory epileptic seizures in the first year of life, global developmental delay, a variable degree of intellectual disability, and dysmorphic facial features not typical of CdLS. This was a descriptive observational study for the largest international cohort with this specific disorder. The main goal of this study was to improve the knowledge of the natural history of this phenotype with particular attention to the psychomotor development and the epilepsy data. The analyzed cohort shows normal prenatal growth with the subsequent development of postnatal microcephaly. The incidence of neonatal problems (seizures and respiratory compromise) is considerable (51.4%). There is a significant prevalence of central nervous system (20%) and cardiovascular malformations (20%). Motor skills are generally delayed. The presence of drug-resistant epilepsy is confirmed; the therapeutic role of a ketogenic diet is still uncertain. The significant regression of previously acquired skills following the onset of seizures has been observed. Facial dysmorphisms are variable and no patient shows a classic CdLS phenotype. To sum up, SMC1A variants caused drug-resistant epilepsy in these patients, more than two-thirds of whom were shown to progress to developmental and epileptic encephalopathy. The SMC1A gene variants are all different from each other (apart from a couple of monozygotic twins), demonstrating the absence of a mutational hotspot in the SMC1A gene. Owing to the absence of phenotypic specificity, whole-exome sequencing is currently the diagnostic gold standard.
Subject(s)
Cell Cycle Proteins , Chromosomal Proteins, Non-Histone , Mutation , Humans , Female , Male , Cell Cycle Proteins/genetics , Chromosomal Proteins, Non-Histone/genetics , Child, Preschool , Infant , Mutation/genetics , Child , Epilepsy/genetics , Epilepsy/epidemiology , Epilepsy/pathology , Epilepsy/diagnosis , Phenotype , Cohort Studies , Adolescent , Infant, Newborn , Epileptic Syndromes/genetics , Epileptic Syndromes/epidemiology , De Lange Syndrome/genetics , De Lange Syndrome/epidemiology , De Lange Syndrome/pathologyABSTRACT
BACKGROUND: Cornelia de Lange Syndrome (CdLS) presents with a variable multi-systemic phenotype and pathogenic variants have been identified in five main genes. This condition has been understudied in African populations with little phenotypic and molecular information available. METHODS AND RESULTS: We present a cohort of 14 patients with clinical features suggestive of CdLS. Clinical phenotyping was carried out and cases were classified according to the international consensus criteria. According to this criteria, nine patients had classical CdLS, one had non-classical CdLS and four presented with a phenotype that suggested molecular testing for CdLS. Each patient underwent mutation profiling using a targeted next generation sequencing panel of 18 genes comprising known and suspected CdLS causal genes. Of the 14 patients tested, pathogenic and likely pathogenic variants were identified in nine: eight variants in the NIPBL gene and one in the STAG1 gene. CONCLUSIONS: We present the first molecular data for a cohort of South African patients with CdLS. Eight of the nine variants identified were in the NIPBL gene, the most commonly involved gene in cases of CdLS. This is also the first report of a patient of African ancestry presenting with STAG1-related CdLS.
Subject(s)
Cell Cycle Proteins , De Lange Syndrome , Humans , Cell Cycle Proteins/genetics , De Lange Syndrome/genetics , De Lange Syndrome/pathology , South Africa , Mutation , PhenotypeABSTRACT
Verheij syndrome [VRJS; OMIM 615583] is a rare autosomal dominant neurodevelopmental disorder characterized by distinct clinical features, including growth retardation, intellectual disability, cardiac, and renal anomalies. VRJS is caused by deletions of chromosome 8q24.3 or pathogenic variants in the PUF60 gene. Recently, pathogenic PUF60 variants have been reported in some individuals with VRJS, contributing to the variability in the clinical presentation and severity of the condition. PUF60 encodes a protein involved in regulating gene expression and cellular growth. In this report, we describe a new case of VRJS with developmental delay, cardiac-, and renal abnormalities, caused by a heterozygous pathogenic PUF60 variant. Surprisingly, DNA methylation analysis revealed a pattern resembling the Cornelia de Lange syndrome (CdLS) episignature, suggesting a potential connection between PUF60 and CdLS-related genes. This case report further delineates the clinical and molecular spectrum of VRJS and supports further research to validate the interaction between VRJS and CdLS.
Subject(s)
De Lange Syndrome , Intellectual Disability , Humans , De Lange Syndrome/diagnosis , De Lange Syndrome/genetics , De Lange Syndrome/pathology , Intellectual Disability/genetics , Phenotype , Cell Cycle Proteins/geneticsABSTRACT
Cornelia de Lange syndrome is a genetic and clinically heterogeneous entity, caused by at least five genes. It is characterized by short stature, gestalt facies, microcephaly, neurodevelopmental disorders, and other anomalies. In this report, we present a 13-year-old female patient with microcephaly, cleft palate, polydactyly, short stature, triangular facies, frontal bossing, a bulbous nose, an overfolded helix, limited pronosupination, and an anomalous uterus. No neurodevelopmental disorders were reported. A chromosomal microarray analysis of 6.5 million markers was performed in the proband and her parents. The results showed a de novo heterozygous microdeletion of exons 9-14 within RAD21, which confirmed the diagnosis of Cornelia de Lange syndrome type 4. Our patient did not show any neurologic phenotype (until the time of diagnosis), although neurodevelopmental disorders are frequently present in patients with Cornelia de Lange syndrome type 4, and despite carrying a deletion that was larger than previously reported. Therefore, unknown genetic modifiers or intrinsic mechanisms of RAD21 variants may exist and should be studied.
Subject(s)
Cell Cycle Proteins , De Lange Syndrome , Gene Deletion , Humans , Female , Adolescent , De Lange Syndrome/genetics , De Lange Syndrome/pathology , Cell Cycle Proteins/genetics , Microarray AnalysisABSTRACT
El síndrome de Cornelia de Lange (SCdL) es un trastorno genético poco frecuente y se atribuye principalmente a mutaciones en los genes NIPBL, SMC3 y SMC1A. Sus principales características clínicas son múltiples anomalías congénitas, dimorfismo facial, hirsutismo, hipertricosis, retraso psicomotor, discapacidad intelectual, restricción del crecimiento prenatal y postnatal, anomalías de manos y pies, así como malformaciones congénitas que afectan a distintos órganos. En pacientes con SCdL es necesario hacer hincapié en la higiene oral debido a la discapacidad intelectual que puede presentarse y asegurarse de que se realiza una adecuada valoración y saneamiento dental de forma periódica con el fin de prevenir enfermedades bucodentales. El objetivo de este reporte de caso es describir el manejo odontológico de un paciente de 10 años con SCdL y revisar las características clínicas y hallazgos radiológicos presentes en la cavidad oral (AU)
Cornelia de Lange syndrome (CdLS) is a rare genetic disorder and is principally attributed to mutations in the NIPBL, SMC3 and SMC1A genes. The main clinical characteristics are multiple congenital anomalies, facial dimorphism, hirsutism, hypertrichosis, psychomotor retardation, intellectual disability, prenatal and postnatal growth restriction, hand and foot anomalies, as well as congenital malformations affecting different organs. In patients with CDLS, it is necessary to focus on oral hygiene due to the intellectual disability that may be present and to ensure that adequate dental valuation and hygiene is routinely performed in order to prevent oral diseases. The aim of this case report is to describe the dental management of a 10-year-old patient with CDLS and review the clinical characteristics and radiological findings that are present in the oral cavity (AU)
Subject(s)
Humans , Female , Child , Oral Manifestations , Dental Care for Chronically Ill/methods , De Lange Syndrome/therapy , De Lange Syndrome/diagnostic imaging , Orthodontics, Corrective/methods , Schools, Dental , Tooth Abnormalities , Dental Care for Children/methods , Maxillofacial Abnormalities , De Lange Syndrome/pathology , MexicoABSTRACT
Cornelia de Lange Syndrome (CdLS) is a rare, dominantly inherited multisystem developmental disorder characterized by highly variable manifestations of growth and developmental delays, upper limb involvement, hypertrichosis, cardiac, gastrointestinal, craniofacial, and other systemic features. Pathogenic variants in genes encoding cohesin complex structural subunits and regulatory proteins (NIPBL, SMC1A, SMC3, HDAC8, and RAD21) are the major pathogenic contributors to CdLS. Heterozygous or hemizygous variants in the genes encoding these five proteins have been found to be contributory to CdLS, with variants in NIPBL accounting for the majority (>60%) of cases, and the only gene identified to date that results in the severe or classic form of CdLS when mutated. Pathogenic variants in cohesin genes other than NIPBL tend to result in a less severe phenotype. Causative variants in additional genes, such as ANKRD11, EP300, AFF4, TAF1, and BRD4, can cause a CdLS-like phenotype. The common role that these genes, and others, play as critical regulators of developmental transcriptional control has led to the conditions they cause being referred to as disorders of transcriptional regulation (or "DTRs"). Here, we report the results of a comprehensive molecular analysis in a cohort of 716 probands with typical and atypical CdLS in order to delineate the genetic contribution of causative variants in cohesin complex genes as well as novel candidate genes, genotype-phenotype correlations, and the utility of genome sequencing in understanding the mutational landscape in this population.
Subject(s)
De Lange Syndrome , Nuclear Proteins , Humans , Nuclear Proteins/genetics , De Lange Syndrome/diagnosis , De Lange Syndrome/genetics , De Lange Syndrome/pathology , Transcription Factors/genetics , Cell Cycle Proteins/genetics , Phenotype , Mutation , Genomics , Genetic Association Studies , Transcriptional Elongation Factors/genetics , Histone Deacetylases/genetics , Repressor Proteins/geneticsABSTRACT
Cornelia de Lange syndrome (CdLS) is a rare multisystem congenital neurodevelopmental disorder (NDD) characterized by distinctive facial anomalies, short stature, developmental delay, hirsutism, gastrointestinal abnormalities and upper limb reduction defects. CdLS syndrome is associated with causative variants in genes encoding for the cohesin complex, a cellular machinery involved in chromatid pairing, DNA repair and gene-expression regulation. In this report, we describe a familial case of a syndromic presentation in a 4-year-old patient (P1) and in his mother (P2). Trio-based Whole Exome Sequencing (WES) performed on P1 was first negative. Since his phenotypic evolution during the follow-up was reminiscent of the CdLS spectrum, a reanalysis of WES data, focused on CdLS-related genes, was requested. Although no alterations in those genes was detected, we identified the likely pathogenetic variant c.40G > A (p.Glu14Lys) in the PHIP gene, in the meanwhile associated with Chung-Jansen syndrome. Reverse phenotyping carried out in both patients confirmed the molecular diagnosis. CHUJANS belongs to NDDs, featuring developmental delay, mild-to-moderate intellectual disability, behavioral problems, obesity and facial dysmorphisms. Moreover, as here described, CHUJANS shows a significant overlap with the CdLS spectrum, with specific regard to facial gestalt. On the basis of our findings, we suggest to include PHIP among genes routinely analyzed in patients belonging to the CdLS spectrum.
Subject(s)
De Lange Syndrome , Intellectual Disability , Humans , Child, Preschool , Cell Cycle Proteins/genetics , De Lange Syndrome/diagnosis , De Lange Syndrome/genetics , De Lange Syndrome/pathology , Phenotype , Gene Expression Regulation , Intellectual Disability/diagnosis , Intellectual Disability/geneticsABSTRACT
Recent studies suggest that transcript isoforms significantly overlap (approximately 60%) between brain tissue and Epstein-Barr virus-transformed lymphoblastoid cell lines (LCLs). Interestingly, 14 cohesion-related genes with variants that cause Cornelia de Lange Syndrome (CdLS) are highly expressed in the brain and LCLs. In this context, we first performed RNA sequencing of LCLs from 22 solved (with pathogenic variants) and 19 unsolved (with no confirmed variants) CdLS cases. Next, an RNA sequencing pipeline was developed using solved cases with two different methods: short variant analysis (for single-nucleotide and indel variants) and aberrant splicing detection analysis. Then, 19 unsolved cases were subsequently applied to our pipeline, and four pathogenic variants in NIPBL (one inframe deletion and three intronic variants) were newly identified. Two of three intronic variants were located at Alu elements in deep-intronic regions, creating cryptic exons. RNA sequencing with LCLs was useful for identifying hidden variants in exome-negative cases.
Subject(s)
De Lange Syndrome , Epstein-Barr Virus Infections , Cell Cycle Proteins/genetics , De Lange Syndrome/diagnosis , De Lange Syndrome/genetics , De Lange Syndrome/pathology , Herpesvirus 4, Human/genetics , Humans , Nucleotides , Phenotype , Protein Isoforms/genetics , Sequence Analysis, RNAABSTRACT
Cornelia de Lange syndrome (CdLS) is a multisystemic genetic disorder characterized by distinctive facial features, growth retardation, and intellectual disability, as well as various systemic conditions. It is caused by genetic variants in genes related to the cohesin complex. Single-nucleotide variations are the best-known genetic cause of CdLS; however, copy number variants (CNVs) clearly underlie a substantial proportion of cases of the syndrome. The NIPBL gene was thought to be the locus within which clinically relevant CNVs contributed to CdLS. However, in the last few years, pathogenic CNVs have been identified in other genes such as HDAC8, RAD21, and SMC1A. Here, we studied an affected girl presenting with a classic CdLS phenotype heterozygous for a de novo ~32 kbp intragenic duplication affecting exon 10 of HDAC8. Molecular analyses revealed an alteration in the physiological splicing that included a 96 bp insertion between exons 9 and 10 of the main transcript of HDAC8. The aberrant transcript was predicted to generate a truncated protein whose accessibility to the active center was restricted, showing reduced ease of substrate entry into the mutated enzyme. Lastly, we conclude that the duplication is responsible for the patient's phenotype, highlighting the contribution of CNVs as a molecular cause underlying CdLS.
Subject(s)
De Lange Syndrome , Cell Cycle Proteins/genetics , De Lange Syndrome/genetics , De Lange Syndrome/pathology , Exons , Heterozygote , Histone Deacetylases/genetics , Humans , Phenotype , Repressor Proteins/geneticsABSTRACT
Cornelia de Lange syndrome (CdLS; MIM# 122470) is a rare developmental disorder. Pathogenic variants in 5 genes explain approximately 50% cases, leaving the other 50% unsolved. We performed whole genome sequencing (WGS) ± RNA sequencing (RNA-seq) in 5 unsolved trios fulfilling the following criteria: (i) clinical diagnosis of classic CdLS, (ii) negative gene panel sequencing from blood and saliva-isolated DNA, (iii) unaffected parents' DNA samples available and (iv) proband's blood-isolated RNA available. A pathogenic de novo mutation (DNM) was observed in a CdLS differential diagnosis gene in 3/5 patients, namely POU3F3, SPEN, and TAF1. In the other two, we identified two distinct deep intronic DNM in NIPBL predicted to create a novel splice site. RT-PCRs and RNA-Seq showed aberrant transcripts leading to the creation of a novel frameshift exon. Our findings suggest the relevance of WGS in unsolved suspected CdLS cases and that deep intronic variants may account for a proportion of them.
Subject(s)
De Lange Syndrome , Humans , De Lange Syndrome/diagnosis , De Lange Syndrome/genetics , De Lange Syndrome/pathology , Diagnosis, Differential , Cell Cycle Proteins/genetics , Introns , Mutation , Sequence Analysis, RNA , PhenotypeABSTRACT
Background: Cornelia de Lange syndrome (CdLS) is a genetic syndrome characterized by intellectual disability, special facial features, growth retardation, feeding difficulties, and multiple organ system abnormalities. NIPBL variants occur in approximately 80% of CdLS cases. Aims: We report a novel de novo heterozygous pathogenic variant in the NIPBL and its association with CdLS. We also examined the key regulatory sequences of the 5' untranslated region in NIPBL mRNA. Few studies have reported mutation sites in the 5' untranslated region (UTR) of the NIPBL that result in CdLS. Methods: The patient's medical history, clinical manifestations, physical examination, laboratory examination, Griffiths development assessment scaleChinese version, and cardiac B-ultrasound were examined. Mutation screening was conducted using trio whole exome sequencing (trio-WES) and Sanger sequencing. Quantitative PCR was performed to measure the NIPBL expression in peripheral blood mononuclear cells. A Dual-Luciferase reporter assay was conducted to evaluate the transcription of truncated mutants. Results: The proband showed characteristics of CdLS including thick eyebrows, a concave nasal ridge, long and smooth philtrum, downturned corners of the mouth, intellectual disability, postnatal growth retardation, and a short fifth toe. A novel de novo heterozygous pathogenic variant in the NIPBL (c.-467C > T) was identified. A Dual-Luciferase reporter gene assay showed that SPO1 (-490 bp to -360 bp) and SPO3 (-490 bp to -401 bp) induced the highest activity. Conclusions: We found a novel de novo heterozygous pathogenic variant (c.-467C > T) in the NIPBL resulting in CdLS. Our findings expand the spectrum of pathogenic mutations for CdLS. Our in vitro experiments elucidated important regulatory sequences in the 5' UTR of the NIPBL.
Subject(s)
De Lange Syndrome , Intellectual Disability , 5' Untranslated Regions , Cell Cycle Proteins/genetics , De Lange Syndrome/diagnosis , De Lange Syndrome/genetics , De Lange Syndrome/pathology , Growth Disorders/genetics , Humans , Intellectual Disability/genetics , Leukocytes, Mononuclear/pathology , Luciferases/geneticsABSTRACT
BRD4 is part of a multiprotein complex involved in loading the cohesin complex onto DNA, a fundamental process required for cohesin-mediated loop extrusion and formation of Topologically Associating Domains. Pathogenic variations in this complex have been associated with a growing number of syndromes, collectively known as cohesinopathies, the most classic being Cornelia de Lange syndrome. However, no cohort study has been conducted to delineate the clinical and molecular spectrum of BRD4-related disorder. We formed an international collaborative study, and collected 14 new patients, including two fetuses. We performed phenotype and genotype analysis, integrated prenatal findings from fetopathological examinations, phenotypes of pediatric patients and adults. We report the first cohort of patients with BRD4-related disorder and delineate the dysmorphic features at different ages. This work extends the phenotypic spectrum of cohesinopathies and characterize a new clinically relevant and recognizable pattern, distinguishable from the other cohesinopathies.
Subject(s)
De Lange Syndrome , Nuclear Proteins , Cell Cycle Proteins/genetics , Child , De Lange Syndrome/diagnosis , De Lange Syndrome/genetics , De Lange Syndrome/pathology , Female , Genomics , Humans , Mutation , Nuclear Proteins/genetics , Phenotype , Pregnancy , Transcription Factors/geneticsABSTRACT
Purpose: Cornelia de Lange syndrome (CdLS) is a rare congenital developmental disorder, and cases caused by variants in SMC3 are infrequent. This article describes a case of CdLS related to a pathogenic variant in SMC3 and performs a literature review. Methods: We collected clinical data and biological samples from a 12-year-old boy with "short stature for 11 years". Gene variants in the proband were detected by whole-exome sequencing, and the variants in his parents were verified by Sanger sequencing. All SMC3-related CdLS patients from the PubMed and Web of Science databases were collected and summarized using the available data. Results: A pathogenic variant in SMC3 in the proband, c.1942A>G, was identified. Neither of his parents carried the same variant. Twenty-eight patients were diagnosed with CdLS with variants in SMC3, including the cases in this study and those reported in the literature, where half of the variant types were missense, followed by 32% (9/28) with a deletion and 11% (3/28) with a duplication. All patients showed symptoms of verbal development delay and intellectual disability to different degrees, and 90% patients had long eyelashes while 89% patients had arched eyebrows. Conclusion: This study summarized different gene variants in SMC3 and the frequencies of the various clinical manifestations according to the reported literature. For CdLS caused by SMC3 variants, short stature and facial dysmorphic features are the two most important clinical clues. Definite diagnosis of this rare disease may be challenging clinically; thus, it is significant to use molecular diagnosis.
Subject(s)
Asian People/genetics , Cell Cycle Proteins/genetics , Chondroitin Sulfate Proteoglycans/genetics , Chromosomal Proteins, Non-Histone/genetics , De Lange Syndrome/pathology , Mutation , De Lange Syndrome/etiology , De Lange Syndrome/metabolism , Humans , Male , Phenotype , Prognosis , Exome SequencingABSTRACT
BACKGROUND: Cornelia de Lange syndrome (CdLS) is a rare and clinically variable syndrome characterized by growth impairment, multi-organ anomalies, and a typical set of facial dysmorphisms. Here we describe a 2-year-old female child harboring a novel de novo missense variant in HDAC8, whose phenotypical score, according to the recent consensus on CdLS clinical diagnostic criteria, allowed the diagnosis of a non-classic CdLS. METHODS: Clinical exome sequencing was performed on the trio, identifying a de novo heterozygous variant in HDAC8 (NM_018486; c. 356C>G p.Thr119Arg). Molecular modeling was performed to evaluate putative functional consequence of the HDAC8 protein. RESULTS: The variant HDAC8 c.356C>G is classified as pathogenic following the ACMG (American College of Medical Genetics and Genomics)/AMP (Association for Molecular Pathology) guidelines. By molecular modeling, we confirmed the deleterious effect of this variant, since the amino acid change compromises the conformational flexibility of the HDAC8 loop required for optimal catalytic function. CONCLUSION: We described a novel Thr119Arg mutation in HDAC8 in a patient displaying the major phenotypic traits of the CdLS. Our results suggest that a modest change outside an active site is capable of triggering global structural changes that propagate through the protein scaffold to the catalytic site, creating de facto haploinsufficiency.
Subject(s)
De Lange Syndrome/genetics , Histone Deacetylases/genetics , Mutation, Missense , Repressor Proteins/genetics , Child, Preschool , De Lange Syndrome/pathology , Female , Histone Deacetylases/chemistry , Humans , Protein Conformation , Repressor Proteins/chemistryABSTRACT
Precocious dissociation of sisters 5 (PDS5) is an associate protein of cohesin that is conserved from yeast to humans. It acts as a regulator of the cohesin complex and plays important roles in various cellular processes, such as sister chromatid cohesion, DNA damage repair, gene transcription, and DNA replication. Vertebrates have two paralogs of PDS5, PDS5A and PDS5B, which have redundant and unique roles in regulating cohesin functions. Herein, we discuss the molecular characteristics and functions of PDS5, as well as the effects of its mutations in the development of diseases and their relevance for novel therapeutic strategies.
Subject(s)
Cell Cycle Proteins/genetics , DNA Repair , DNA-Binding Proteins/genetics , De Lange Syndrome/genetics , Neoplasms/genetics , Nuclear Proteins/genetics , Saccharomyces cerevisiae Proteins/genetics , Transcription Factors/genetics , Animals , Cell Cycle Proteins/chemistry , Cell Cycle Proteins/metabolism , Conserved Sequence , DNA Damage , DNA Replication , DNA-Binding Proteins/chemistry , DNA-Binding Proteins/metabolism , De Lange Syndrome/metabolism , De Lange Syndrome/pathology , Gene Expression , Humans , Mice , Mice, Knockout , Models, Molecular , Neoplasms/metabolism , Neoplasms/pathology , Nuclear Proteins/chemistry , Nuclear Proteins/metabolism , Protein Structure, Secondary , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/metabolism , Saccharomyces cerevisiae Proteins/chemistry , Saccharomyces cerevisiae Proteins/metabolism , Sister Chromatid Exchange , Transcription Factors/chemistry , Transcription Factors/metabolismABSTRACT
OBJECTIVE: To carry out genetic testing for an abortus suspected with Cornelia de Lange syndrome (CdLS). METHODS: History of gestation and the family was taken. Combined with prenatal ultrasonography and the phenotype of the abortus, a diagnosis was made for the proband. Fetal tissue and peripheral blood samples of its parents were collected for the extraction of genomic DNA. Whole exome sequencing was carried out to detect mutations related to the phenotype. Suspected mutations were verified in the parents through Sanger sequencing. RESULTS: Prenatal ultrasound found that the forearms and hands of the fetus were anomalous, in addition with poorly formed vermis cerebellum, slight micrognathia, and increased echo of bilateral renal parenchyma. Examination of the abortus has noted upper limb and facial malformations. Whole exome sequencing revealed that the fetus carried a heterozygous c.2118delG (p.Lys706fs) frameshift mutation of the NIPBL gene. The same mutation was not found in either parent. CONCLUSION: The heterozygous c.2118delG (p.Lys706fs) frameshift mutation of the NIPBL gene probably underlies the CdLS in the fetus. Above finding has provided a basis for the genetic counseling for the family.
Subject(s)
De Lange Syndrome , Mutation , Cell Cycle Proteins/genetics , DNA Mutational Analysis , De Lange Syndrome/genetics , De Lange Syndrome/pathology , Female , Fetus , Humans , Male , Phenotype , Pregnancy , Exome SequencingABSTRACT
OBJECTIVE@#To carry out genetic testing for an abortus suspected with Cornelia de Lange syndrome (CdLS).@*METHODS@#History of gestation and the family was taken. Combined with prenatal ultrasonography and the phenotype of the abortus, a diagnosis was made for the proband. Fetal tissue and peripheral blood samples of its parents were collected for the extraction of genomic DNA. Whole exome sequencing was carried out to detect mutations related to the phenotype. Suspected mutations were verified in the parents through Sanger sequencing.@*RESULTS@#Prenatal ultrasound found that the forearms and hands of the fetus were anomalous, in addition with poorly formed vermis cerebellum, slight micrognathia, and increased echo of bilateral renal parenchyma. Examination of the abortus has noted upper limb and facial malformations. Whole exome sequencing revealed that the fetus carried a heterozygous c.2118delG (p.Lys706fs) frameshift mutation of the NIPBL gene. The same mutation was not found in either parent.@*CONCLUSION@#The heterozygous c.2118delG (p.Lys706fs) frameshift mutation of the NIPBL gene probably underlies the CdLS in the fetus. Above finding has provided a basis for the genetic counseling for the family.
Subject(s)
Female , Humans , Male , Pregnancy , Cell Cycle Proteins/genetics , DNA Mutational Analysis , De Lange Syndrome/pathology , Fetus , Mutation , Phenotype , Exome SequencingABSTRACT
BACKGROUND: Cornelia de Lange syndrome (CdLS) is a rare congenital developmental disorder with variable multisystem involvement and genetic heterogeneity. We aimed to analyze the clinical and genetic characteristics of Chinese individuals with CdLS. METHODS: We collected data regarding the neonatal period, maternal status, clinical manifestation, including facial dimorphisms and development, and follow-up treatment for individuals diagnosed with CdLS. In individuals with suspected CdLS, high-throughput sequencing, Sanger sequencing, and real-time qualitative PCR were used to verify the diagnosis. RESULTS: Variants, including six that were novel, were concentrated in the NIPBL (70%), HDAC8 (20%), and SMC3 (10%) genes. We found two nonsense, three splicing, and two deletion variants in NIPBL; a missense variant and an absence variant in HDAC8; and a missense variant in SMC3. Eleven cardinal features of CdLS were present in more than 80% of Chinese individuals. Compared with non-Chinese individuals of diverse ancestry, there were significant differences in the clinical characteristics of eight of these features. CONCLUSION: Six novel pathological variants were identified; thus, the study expanded the gene variant spectrum. Furthermore, most cardinal features of CdLS found in Chinese individuals were also found in individuals from other countries. However, there were significant differences in eight clinical features.