Cornelia de Lange Spectrum.

Cornelia de Lange syndrome (CdLS) is a rare congenital developmental disorder with multisystemic involvement. The clinical presentation is highly variable, but the classic phenotype, characterized by distinctive craniofacial features, pre- and postnatal growth retardation, extremity reduction defects, hirsutism and intellectual disability can be distinguished from the nonclassic phenotype, which is generally milder and more difficult to diagnose. In addition, the clinical features overlap with those of other neurodevelopmental disorders, so the use of consensus clinical criteria and artificial intelligence tools may be helpful in confirming the diagnosis. Pathogenic variants in NIPBL, which encodes a protein related to the cohesin complex, have been identified in more than 60% of patients, and pathogenic variants in other genes related to this complex in another 15%: SMC1A, SMC3, RAD21, and HDAC8. Technical advances in large-scale sequencing have allowed the description of additional genes (BRD4, ANKRD11, MAU2), but the lack of molecular diagnosis in 15% of individuals and the substantial clinical heterogeneity of the syndrome suggest that other genes and mechanisms may be involved. Although there is no curative treatment, there are symptomatic/palliative treatments that paediatricians should be aware of. The main medical complication in classic SCdL is gastro-esophageal reflux (GER), which should be treated early.

Novel PUF60 variant suggesting an interaction between Verheij and Cornelia de Lange syndrome: phenotype description and review of the literature.

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.

Comprehensive review and expanding the genetic landscape of Cornelia-de-Lange spectrum: insights from novel mutations and skin biopsy in exome-negative cases.

BACKGROUND: Cornelia de Lange Syndrome (CdLS) is a rare genetic disorder characterized by a range of physical, cognitive, and behavioral abnormalities. This study aimed to perform a comprehensive review of the literature on CdLS and investigate two cases of CdLS with distinct phenotypes that underwent WES to aid in their diagnosis. METHODS: We conducted a comprehensive review of the literature on CdLS along with performing whole-exome sequencing on two CdLS patients with distinct phenotypes, followed by Sanger sequencing validation and in-silico analysis. RESULTS: The first case exhibited a classic CdLS phenotype, but the initial WES analysis of blood-derived DNA failed to identify any mutations in CdLS-related genes. However, a subsequent WES analysis of skin-derived DNA revealed a novel heterozygous mutation in the NIPBL gene (NM_133433.4:c.6534_6535del, p.Met2178Ilefs*8). The second case was presented with a non-classic CdLS phenotype, and WES analysis of blood-derived DNA identified a heterozygous missense variant in the SMC1A gene (NM_006306.4:c.2320G>A, p.Asp774Asn). CONCLUSIONS: The study shows the importance of considering mosaicism in classic CdLS cases and the value of WES for identifying genetic defects. These findings contribute to our understanding of CdLS genetics and underscore the need for comprehensive genetic testing to enhance the diagnosis and management of CdLS patients.

Double somatic mosaicism in Cornelia de Lange syndrome.

Post-zygotic mosaicism is a well-known biological phenomenon characterized by the presence of genetically distinct lineages of cells in the same individual due to post-zygotic de novo mutational events. It has been identified in about 13% of Cornelia de Lange (CdLS) syndrome patients with a molecular diagnosis, an unusual high frequency. Here, we report the case of a patient affected by classic CdLS harboring post-zygotic mosaicism for two different likely pathogenic variants at the same nucleotide position in NIPBL. Double somatic mosaicism has never been reported in CdLS and only rarely recognized in human diseases. Possible pathogenetic mechanisms are discussed.

Nasal polyposis in pediatric patients with Cornelia de Lange syndrome: endoscopic diagnosis, treatment and follow up in two case reports.

BACKGROUND: Cornelia de Lange syndrome is a rare genetic disease with otolaryngological involvement. The classic phenotype is characterized by distinctive facial features, intellectual disability, growth delay, hirsutism, and upper-limb reduction. Nasal polyposis was previously reported in association with chronic rhinosinusitis, however data about prevalence, diagnosis, treatment and prognosis are lacking for this cohort of patients, affected by rare disease. CASE PRESENTATION: We describe the whole diagnostic and therapeutic workflow of nasal polyps in two pediatric patients with Cornelia de Lange, successfully diagnosed and treated by nasal endoscopy. CONCLUSION: Our report confirm that nasal endoscopy is a safe and useful tool in the diagnosis, treatment and follow-up of nasal polyps, even in Cornelia de Lange syndrome pediatric patients. We want to increase the alert for the detection of nasal polyps in patients with Cornelia de Lange syndrome since pediatric age. We recommend endoscopy in all patients with Cornelia de Lange syndrome and symptoms of chronic nasal obstruction and/or OSAS. Multidisciplinary team and sedation service could be useful in the management of Cornelia de Lange syndrome patients with airway obstruction symptoms and sleep disturbance when severe intellectual disability, autism or psychiatric findings are present.

Coats' Disease in a Patient With Cornelia de Lange Syndrome: Management With Laser and Bevacizumab.

Cornelia de Lange syndrome is a congenital disorder with multisystem abnormalities including multiple ocular findings. The authors report a case of Coats' disease in a patient with Cornelia de Lange syndrome who was successfully treated with laser and intravitreal bevacizumab. This case demonstrates the importance of fluorescein angiography in making the diagnosis and directing treatment and the efficacy of combined laser with intravitreal anti-vascular endothelial growth factor therapy for persistent vascular leakage associated with Coats' disease in Cornelia de Lange syndrome. [J Pediatr Ophthalmol Strabismus. 2023;60(4):e45-e48.].

Genomic analyses in Cornelia de Lange Syndrome and related diagnoses: Novel candidate genes, genotype-phenotype correlations and common mechanisms.

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.

[Analysis of clinical phenotype and pathogenic variant of a fetus with Cornelia de Lange syndrome type II].

OBJECTIVE: To explore the prenatal ultrasonographic features and genetic basis for an abortus suspected for type II Cornelia de Lange syndrome (CdLS2). METHODS: A fetus diagnosed with CdLS2 at the Shengjing Hospital Affiliated to China Medical University on September 3, 2019 was selected as the study subject. Clinical data of the fetus and family history was collected. Following induced labor, whole exome sequencing was carried out on the abortus. Candidate variant was verified by Sanger sequencing and bioinformatic analysis. RESULTS: Prenatal ultrasonography (33 weeks of pregnancy) has revealed multiple anomalies in the fetus, which included slightly widened cavity of septum pellucidum, blurred corpus callosum, slightly reduced frontal lobe volume, thin cortex, fusion of lateral ventricles, polyhydramnios, small stomach bubble, and digestive tract atresia. Whole exome sequencing has revealed a heterozygous c.2076delA (p.Lys692Asnfs*27) frameshifting variant in the SMC1A gene, which was found in neither parent and was rated as pathogenic based on the guidelines of American College of Medical Genetics and Genomics (ACMG). CONCLUSION: The CdLS2 in this fetus may be attributed to the c.2076delA variant of the SMC1A gene. Above finding has provided a basis for genetic counseling and assessment of reproductive risk for this family.

Chung-Jansen syndrome can mimic Cornelia de Lange syndrome: Another player among chromatinopathies?

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.

A Novel Variant in RAD21 in Cornelia De Lange Syndrome Type 4: Case Report and Bioinformatic Analysis.

Cornelia de Lange Syndrome (CdLS) is a rare genetic disorder that affects many organs. The diagnosis of this condition is primarily clinical and it can be confirmed by molecular analysis of the genes known to cause this disease, although about 30% of CdLS patients are without a genetic diagnosis. Here we report clinical and genetic findings of a patient with CdLS type 4, a syndrome of which the clinical features of only 30 patients have been previously described in the literature. The index patient presented with clinical characteristics previously associated with CdLS type 4 (short nose, thick eyebrow, global development delay, synophrys, microcephaly, weight < 2DS, small hands, height < 2DS). She also presented cardiac anomalies, cleft palate and laryngomalacia, which was never described before. The index patient was diagnosed with a novel de novo RAD21 variant (c.1722_1723delTG, p.Gly575SerfsTer2): segregation analysis, bioinformatic analysis, population data and in silico structural modelling indicate the pathogenicity of the novel variant. This report summarizes previously reported clinical manifestations of CdLS type 4 but also highlights new clinical symptoms, which will aid correct counselling of future CdLS type 4 cases.

[Analysis of genotypes and phenotypes of three children with Cornelia de Lange syndrome].

OBJECTIVE: To analyze the clinical phenotype and results of genetic testing in three children with Cornelia de Lange syndrome (CdLS). METHODS: Clinical data of the children and their parents were collected. Peripheral blood samples of the pedigrees were collected for next generation sequencing analysis. RESULTS: The main clinical manifestations of the three children have included growth delay, mental retardation, peculiar facies and other accompanying symptoms. Based on the criteria proposed by the International Diagnostic Consensus, all three children were suspected for CdLS. As revealed by whole exome sequencing, child 1 has harbored NIPBL gene c.5567_5569delGAA insTAT missense variant, child 2 has harbored SMC1A gene c.607A>G missense variant, and child 3 has harbored HDAC8 gene c.628+1G>A splicing variant. All of the variants were de novo in origin. CONCLUSION: All of the children were diagnosed with CdLS due to pathogenic variants of the associated genes, among which the variants of NIPBL and HDAC8 genes were unreported previously. Above finding has enriched the spectrum of pathogenic variants underlying CdLS.

The developmental trajectories of the behavioral phenotype and neuropsychiatric functioning in Cornelia de Lange and Rubinstein Taybi syndromes: A longitudinal study.

Several changes in the behavioral phenotype arise with the growth of children affected by Cornelia de Lange Syndrome (CdLS) and Rubinstein-Taybi Syndrome (RSTS). However, previous research relied on a cross-sectional study design turning into age-related comparisons of different syndromic cohorts to explore age-dependent changes. We aim to outline the variating pathways of the neuropsychiatric functioning across the lifespan in CdLS and RSTS, through the setting up of a longitudinal study design. The sample included 14 patients with CdLS and 15 with RSTS. The assessments were carried out in two different timepoints. Our findings highlight that the cognitive profile of CdLS is subjected to a worsening trend with decreasing Intellectual Quotient (IQ) scores from T0 to T1, whereas RSTS shows a stable IQ over time. Patients affected by RSTS show greater improvements compared to CdLS in communication, daily living skills, social abilities, and motor skills across the lifespan. Both syndromes report an upward trend in behavioral and emotional difficulties even if CdLS exhibit a significant and major deterioration compared to individuals with RSTS. Being aware of the early dysfunctional patterns which might pave the way for later neuropsychiatric impairments is the first step for planning preventive interventions.

[Prenatal diagnosis and genetic analysis of a fetus with Cornelia de Lange syndrome type 1 due to a splicing variant of NIPBL gene].

OBJECTIVE: To explore the genetic etiology of a fetus with Cornelia de Lange syndrome type 1. METHODS: Clinical data of the fetus was collected. Genomic DNA was extracted from amniotic fluid and peripheral blood samples of the parents and subjected to low-depth copy number variant sequencing, whole exome sequencing (WES) and Sanger sequencing. Pathogenicity of the candidate variant was predicted based on the guidelines of American College of Medical Genetics and Genomics (ACMG). Minigene assay was used to assess the effect of the variant on mRNA splicing. RESULTS: WES revealed that the fetus has harbored a heterozygous c.5808+5gG>A variant in the intron of the NIPBL gene, which was predicted to affect the mRNA splicing. The same variant was not detected in either parent. The variant was not recorded in ExAC, 1000G and dbSNP databases. Comprehensive analysis showed that the variant was deleterious and may result in skipping of exon 31 during mRNA splicing. CONCLUSION: The fetus was diagnosed with Cornelia de Lange syndrome type 1. Splicing variant identified by WES may be verified by minigene assay in vitro, which can provide more evidence for the prediction of its pathogenicity.

Congenital vaginal obstruction in a female with Cornelia de Lange syndrome: A case report.

Cornelia de Lange syndrome (CdLS) is a rare genetic disease involving multiorgan systems that varies in clinical manifestations. Female genital abnormalities in patients with CdLS are rarely reported, and current guidelines for CdLS contain little information related to female genital abnormalities. We report a case of classic CdLS with an NIPBL gene pathogenic variant in a 4.5-year-old girl who experienced recurrent urinary tract infections (UTIs) with vesical tenesmus. Urogenital physical and imaging examinations revealed external vaginal orifice obstruction and bilateral vesicoureteral reflux (VUR). Vaginal diaphragm-like tissue resection and vaginal orifice plasty were performed on this patient. The symptoms of urination disorders and recurrent UTIs, as well as VUR grading, improved after relieving the vaginal obstruction during the operation. For female CdLS patients, especially those with VUR, it is necessary to check for genital abnormalities and perform timely treatment, which is of great significance in improving urination disorder symptoms, reducing resistance during voiding, decreasing the occurrence of secondary VUR, and controlling recurrent UTIs.

Pathogenic variants detected by RNA sequencing in Cornelia de Lange syndrome.

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.

Deep intronic NIPBL de novo mutations and differential diagnoses revealed by whole genome and RNA sequencing in Cornelia de Lange syndrome patients.

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.

Cornelia de Lange Syndrome.

Cornelia de Lange syndrome (CdLS) is a rare, multifactorial, multisystem disorder that affects approximately 1/10,000-100,000 newborns. Mutations and/or variants have been identified in seven genes that have been associated with the diagnosis of this disorder. As all of them affect the cohesin complex, CdLS is also referred to as a "transcriptomopathy" or "cohesinopathy." The phenotype and presentation vary greatly, though there is a classic phenotype that includes a distinctive craniofacial appearance and growth pattern in addition to limb malformations. Because there are multiple overlapping phenotypes with Cornelia de Lange syndrome and other syndromes and sequences, early diagnosis and management of Cornelia de Lange syndrome is imperative. This will enhance the quality of life for individuals with this disorder, as many are now likely to live well into adulthood.

A Novel de Novo Variant in 5' UTR of the NIPBL Associated with Cornelia de Lange Syndrome.

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.

uORF-introducing variants in the 5'UTR of the NIPBL gene as a cause of Cornelia de Lange syndrome.

Cornelia de Lange syndrome (CdLS) is a clinically-recognizable rare developmental disorder. About 70% of patients carry a missense or loss-of-function pathogenic variant in the NIPBL gene. We hypothesized that some variants in the 5'-untranslated region (UTR) of NIPBL may create an upstream open reading frame (uORF), putatively leading to a loss of function. We searched for NIPBL 5'-UTR variants potentially introducing uORF by (i) reannotating NGS data of 102 unsolved CdLS patients and (ii) literature and variant databases search. We set up a green fluorescent protein (GFP) reporter assay and studied NIPBL expression in a lymphoblastoid cell line (LCL). We identified two variants introducing a novel ATG codon sequence in the 5'-UTR of NIPBL, both predicted to introduce uORF: a novel c.-457_-456delinsAT de novo mutation in a 15-year-old male with classic CdLS, and a c.-94C>T variant in a published family. Our reporter assay showed a significant decrease of GFP levels in both mutant contexts, with similar levels of messenger RNA (mRNA) as compared to wt constructs. Assessment of LCL of one patient showed consistent results with decreased NIPBL protein and unchanged mRNA levels. 5'-UTR uORF-introducing NIPBL variants may represent a rare source of pathogenic variants in unsolved CdLS patients.