Immunologic features of Cornelia de Lange syndrome

Chromatinopathies: insight in clinical aspects and underlying epigenetic changes

Chromatinopathies (CPs), a group of rare inborn defects characterized by chromatin state imbalance, have evolved from initially resembling Cornelia de Lange syndrome to encompass a wide array of genetic diseases with diverse clinical presentations. The CPs classification now includes human developmental disorders caused by germline mutations in epigenes, genes that regulate the epigenome. Recent advances in next-generation sequencing have enabled the association of 154 epigenes with CPs, revealing distinctive DNA methylation patterns known as episignatures.It has been shown that episignatures are unique for a particular CP or share similarities among specific CP subgroup. Consequently, these episignatures have emerged as promising biomarkers for diagnosing and treating CPs, differentiating subtypes, evaluating variants of unknown significance, and facilitating targeted therapies tailored to the underlying epigenetic dysregulation.The following review was conducted to collect, summarize, and analyze data regarding CPs in such aspects as clinical evaluation encompassing long-term patient care, underlying epigenetic changes, and innovative molecular and bioinformatic methodologies that have been devised for the assessment of CPs. We have also shed light on promising novel treatment options that have surfaced in recent research and presented a synthesis of ongoing clinical trials, contributing to the current understanding of the dynamic and evolving nature of CPs investigation.

Pneumonia-Induced Thyroid Crisis With Thyrotoxicosis Exacerbation: De Novo Graves' Disease Presentation on a Cornelia de Lange Syndrome (CdLS)

Cornelia de Lange syndrome (CdLS) is a rare genetic disorder that affects multiple organ systems and is characterized by distinctive facial features, growth retardation, and developmental disabilities. The syndrome is caused by mutations in genes (NIPBL, RAD21, SMC3, HDAC8, and SMC1A) involved in the cohesin complex, which plays a critical role in chromosome segregation and gene expression regulation. Clinical findings typically include dysmorphic facial features (arched eyebrows, synophrys, long eyelashes, ptosis, long philtrum, thin upper lip, and posteriorly rotated ears), growth and mental retardation, upper limb defects (clinodactyly and limb deficiencies), gastrointestinal complications (gastroesophageal reflux, pyloric stenosis, diaphragmatic hernia, malrotation, and volvulus), and heart defects (ventricular and atrial septal defects). In addition, chronic respiratory tract infections including sinusitis and pneumonia have been frequently described in this population. The early recognition and diagnosis of CdLS through genetic testing are crucial to ensure appropriate medical management and early intervention therapies to improve the outcomes of affected individuals. The thyroid gland is not affected by this congenital disease, but complications can arrive in this organ by other disease-related organ malfunctions. Pneumonia-induced thyroiditis is a potentially life-threatening condition that can occur in patients with underlying thyroid disease who also develop pneumonia. The symptoms are due to the hypermetabolic state induced by excess thyroid hormones and include weight loss, heat intolerance, and palpitations. There are many different causes of thyrotoxicosis. It is important to determine the cause since treatment is based on the underlying etiology. The diagnosis of pneumonia-induced thyrotoxicosis can be challenging as symptoms may mimic other conditions and laboratory testing may not always provide a clear answer. The diagnosis is confirmed with low thyroid-stimulating hormone (TSH) and elevated free thyroxine (T4) and triiodothyronine (T3), erythrocyte sedimentation rate (ESR), and C-reactive protein. The management of the condition involves prompt recognition, supportive care, and the use of medications to lower thyroid hormone levels, such as beta-blockers, antithyroid drugs, steroids, and iodine. In severe cases, plasmapheresis or thyroidectomy may be necessary.

Cornelia de Lange Syndrome: From a Disease to a Broader Spectrum

Cornelia de Lange syndrome (CdLS) is a genetic disease that exemplifies the evolution of knowledge in the field of rare genetic disorders. Originally described as a unique pattern of major and minor anomalies, over time this syndrome has been shown to be characterized by a significant variability of clinical expression. By increasing the number of patients described, knowledge of the natural history of the condition has been enriched with the demonstration of the relative frequency of various potential comorbidities. Since 2006, the discovery of CdLS's molecular basis has shown an equally vast genetic heterogeneity linked to the presence of variants in genes encoding for the cohesin complex pathway. The most recent clinical-genetic data led to the classification of the "original syndrome" into a "clinical spectrum" that foresees the presence of classic patients, of non-classic forms, and of conditions that show a modest phenotypic overlapping with the original disease. Finally, the knowledge of the molecular basis of the disease has allowed the development of basic research projects that could lay the foundations for the development of possible innovative pharmacological treatments.

Gene alterations as predictors of radiation-induced toxicity in head and neck squamous cell carcinoma

Background

Optimizing the therapeutic ratio for radiation therapy (RT) in head and neck squamous cell carcinoma (HNSCC) is uniquely challenging owing to high rates of early and late toxicity involving nearby organs at risk. These toxicities have a profound impact on treatment compliance and quality of life. Emerging evidence suggests that RT dose alone cannot fully account for the variable severity of RT-related adverse events (rtAEs) observed in HNSCC patients. Next-generation sequencing has become an increasingly valuable tool with widespread use in the oncology field and is being robustly explored for predicting rtAEs beyond dosimetric data.

Methods

Patients who had Foundation Medicine sequencing data and received RT for primary or locally recurrent HNSCC were selected for this study. Early and late toxicity data were collected and reported based on Common Terminology Criteria for Adverse Events version 5.0. Dosimetric parameters were collected for pertinent structures.

Results

A total of HNSCC 37 patients were analyzed in this study. Genetic alterations in BRCA2, ERBB3, NOTCH1 and CCND1 were all associated with higher mean grade of toxicity with BRCA2 alteration implicated in all toxicity parameters evaluated including mucositis, early dysphagia, xerostomia and to a lesser extent, late dysphagia. Interestingly, patients who exhibited alterations in both BRCA2 and ERBB3 experienced a twofold or greater increase in early dysphagia, early xerostomia and late dysphagia compared to ERBB3 alteration alone. Furthermore, several gene alterations were associated with improved toxicity outcomes. Within an RT supersensitive patient subset, alterations were found in TNFAIP3, HNF1A, SPTA1 and CASP8. All of these alterations were not found in the RT insensitive patient subset. We found 17 gene alterations in the RT insensitive patient subset that were not found in the RT supersensitive patient subset.

Conclusion

Despite consistent RT dosimetric parameters, patients with HNSCC experience heterogeneous patterns of rtAEs. Identifying factors associated with toxicity outcomes offers a new avenue for personalized precision RT therapy and prophylactic management. Here, next-generation sequencing in a population of HNSCC patients correlates several genetic alterations with severity of rtAEs. Further analysis is urgently needed to identify genetic patterns associated with rtAEs in order to reduce harmful outcomes in this challenging population.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-02876-5.

SCID newborn screening: What we've learned

Newborn screening for severe combined immunodeficiency, the most profound form of primary immune system defects, has long been recognized as a measure that would decrease morbidity and improve outcomes by helping patients avoid devastating infections and receive prompt immune-restoring therapy. The T-cell receptor excision circle test, developed in 2005, proved to be successful in pilot studies starting in the period 2008 to 2010, and by 2019 all states in the United States had adopted versions of it in their public health programs. Introduction of newborn screening for severe combined immunodeficiency, the first immune disorder accepted for population-based screening, has drastically changed the presentation of this disorder while providing important lessons for public health programs, immunologists, and transplanters.

Case Report: Endogenous Candida Endophthalmitis in Cornelia de Lange Syndrome: Atypical Stellate Neuroretinitis

SIGNIFICANCE

This study aimed to highlight the association of stellate neuroretinitis occurring secondary to endogenous candidemia.

PURPOSE

We report an unusual presentation of endogenous Candida endophthalmitis as a stellate neuroretinitis in the setting of Cornelia de Lange syndrome.

CASE REPORT

A 34-month-old girl with severe Cornelia de Lange syndrome and a history of parenteral nutrition dependence requiring a chronic central venous catheter presented with bilateral endophthalmitis secondary to candidemia. In one eye, the endophthalmitis had the atypical presentation as a stellate neuroretinitis.

CONCLUSIONS

This case represents a unique association of stellate neuroretinitis secondary to Candida infection in a patient with Cornelia de Lange syndrome.

Analysis of clinical and genetic characteristics in 10 Chinese individuals with Cornelia de Lange syndrome and literature review

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.

The Implications of Genetic Testing on Radiation Therapy Decisions: A Guide for Radiation Oncologists

The advent of affordable and rapid next-generation DNA sequencing technology, along with the US Supreme Court ruling invalidating gene patents, has led to a deluge of germline and tumor genetic variant tests that are being rapidly incorporated into clinical cancer decision-making. A major concern for clinicians is whether the presence of germline mutations may increase the risk of radiation toxicity or secondary malignancies. Because scarce clinical data exist to inform decisions at this time, the American Society for Radiation Oncology convened a group of radiation science experts and clinicians to summarize potential issues, review relevant data, and provide guidance for adult patients and their care teams regarding the impact, if any, that genetic testing should have on radiation therapy recommendations. During the American Society for Radiation Oncology workshop, several main points emerged, which are discussed in this manuscript: (1) variants of uncertain significance should be considered nondeleterious until functional genomic data emerge to demonstrate otherwise; (2) possession of germline alterations in a single copy of a gene critical for radiation damage responses does not necessarily equate to increased risk of radiation-induced toxicity; (3) deleterious ataxia-telangiesctasia gene mutations may modestly increase second cancer risk after radiation therapy, and thus follow-up for these patients after indicated radiation therapy should include second cancer screening; (4) conveying to patients the difference between relative and absolute risk is critical to decision-making; and (5) more work is needed to assess the impact of tumor somatic alterations on the probability of response to radiation therapy and the potential for individualization of radiation doses. Data on radiosensitivity related to specific genetic mutations is also briefly discussed.

Cornelia de lange manifestations in otolaryngology: A systematic review and meta-analysis

OBJECTIVES

Cornelia de Lange syndrome (CdLS) is a rare genetic disorder. Our goal was to systematically review the literature regarding otolaryngology manifestations of CdLS.

METHODS

We systematically reviewed the PubMed, Embase, CINAHL, Scopus, and Google Scholar databases for original articles of otolaryngology manifestations for patients with CdLS. These articles were analyzed, and pooled prevalence was calculated.

RESULTS

We analyzed 1,310 patients included in 35 case series and 34 case reports. Hearing loss was present for many patients (27 studies), with sensorineural hearing loss affecting 40.3% (95% confidence interval [CI]: 17.3-63.4) and conductive affecting 22.7% (95% CI: 5.7-39.7). Recurrent acute otitis media was the most frequent infectious manifestation, with 56.5% (95% CI: 34.1-78.4) in seven studies, followed by recurrent airway infections with 44.1% (95% CI: 11.0-87.1) in five studies. Forty-nine (49.7%) percent of patients (95% CI: 25.9-73.6) in nine studies had dysphagia, and 76.6% (95% CI: 59.8-93.3) in four studies had some degree of dysphonia. Craniofacial anomalies were reported in 30 studies, with micrognathia (53.1%; 95% CI: 34.1-72.1) and high arched palate (70.6%; 95% CI: 56.5-84.8) commonly reported. Additional physical exam abnormalities reported included those involving: lips (76.8%; 95% CI: 65.3-88.4), dentition (65.1%; 95% CI: 27.2-100), mouth (85.5%; 95% CI: 76.2-93.8), and eyelashes (87.1%; 95% CI: 77.2-96.9). Sleep-disordered breathing or obstructive sleep apnea affected 25.8% (95% CI: 11.4-40.2) of patients (7 studies). Airway anomalies were reported in 11 case reports.

CONCLUSION

This is the first comprehensive evaluation of otolaryngologic manifestations in the CdLS literature. Most reported hearing loss and craniofacial anomalies. Sleep disorders occurred in a minority of patients, whereas airway disorders were primarily reported in case reports. These conditions should be further examined given their potential life-threatening implications.

LEVEL OF EVIDENCE

3a Laryngoscope, 130:E122-E133, 2020.

Reference intervals for lymphocyte subsets in preterm and term neonates without immune defects

BACKGROUND

In 6.5 years of newborn screening for severe combined immunodeficiency in California, 3,252,156 infants had DNA from dried blood spots (DBSs) assayed for T-cell receptor excision circles. Infants with T-cell receptor excision circle values of less than a designated cutoff on a single DBS, 2 DBS samples with insufficient PCR amplification, or known genetic risk of immunodeficiency had peripheral blood complete blood counts and lymphocyte subsets assayed in a single flow cytometry laboratory. Cases in which immune defects were ruled out were available for analysis.

OBJECTIVE

We sought to determine reference intervals for lymphocyte subsets in racially/ethnically diverse preterm and term newborns who proved to be unaffected by any T-lymphopenic immune disorder.

METHODS

Effective gestational age (GA) was defined as GA at birth plus postnatal age at the time of sample collection. After determining exclusion criteria, we analyzed demographic and clinical information, complete and differential white blood cell counts, and lymphocyte subsets for 301 infants, with serial measurements for 33 infants. Lymphocyte subset measurements included total T cells, helper and cytotoxic T-cell subsets, naive and memory phenotype of each T-cell subset, B cells, and natural killer cells.

RESULTS

Reference intervals were generated for absolute numbers and lymphocyte subsets from infants with effective GAs of 22 to 52 weeks. Sex and ethnicity were not significant determinants of lymphocyte subset counts in this population. Lymphocyte counts increased postnatally.

CONCLUSION

This study provides a baseline for interpreting comprehensive lymphocyte data in preterm and term infants, aiding clinicians to determine which newborns require further evaluations for immunodeficiency.

Diagnosis and management of Cornelia de Lange syndrome: first international consensus statement

Cornelia de Lange syndrome (CdLS) is an archetypical genetic syndrome that is characterized by intellectual disability, well-defined facial features, upper limb anomalies and atypical growth, among numerous other signs and symptoms. It is caused by variants in any one of seven genes, all of which have a structural or regulatory function in the cohesin complex. Although recent advances in next-generation sequencing have improved molecular diagnostics, marked heterogeneity exists in clinical and molecular diagnostic approaches and care practices worldwide. Here, we outline a series of recommendations that document the consensus of a group of international experts on clinical diagnostic criteria, both for classic CdLS and non-classic CdLS phenotypes, molecular investigations, long-term management and care planning.

Herpes Simplex Virus Esophagitis in Immunocompetent Children: A Harbinger of Eosinophilic Esophagitis?

Herpes simplex virus (HSV) is a common cause of infectious esophagitis. The aim of this retrospective study is to identify comorbid and predisposing conditions and sequelae of HSV esophagitis in immunocompetent children. We reviewed 16 cases of HSV esophagitis diagnosed from January 1982 to March 2016. Five patients were immunosuppressed, 11 were immunocompetent and included in the study. Three (27%) had no other significant medical history. Five patients (45%) had repeat biopsies following their HSV infection, which showed eosinophilic infiltrate consistent with current diagnostic criteria of eosinophilic esophagitis (EoE), one of whom had known EoE. Environmental allergies and/or asthma were present in 4 of 5 of these patients. Among the immunocompetent patients, EoE was a comorbidity in almost half, although biopsies at the time of HSV esophagitis did not show diagnostic features of EoE. Clinical follow-up is therefore warranted for immunocompetent children presenting with HSV esophagitis, particularly those with atopic conditions.

Inhibition of the lytic cycle of Kaposi's sarcoma-associated herpesvirus by cohesin factors following de novo infection

Establishment of Kaposi's sarcoma-associated herpesvirus (KSHV) latency following infection is a multistep process, during which polycomb proteins are recruited onto the KSHV genome, which is crucial for the genome-wide repression of lytic genes during latency. Strikingly, only a subset of lytic genes are expressed transiently in the early phase of infection prior to the binding of polycomb proteins onto the KSHV genome, which raises the question what restricts lytic gene expression in the first hours of infection. Here, we demonstrate that both CTCF and cohesin chromatin organizing factors are rapidly recruited to the viral genome prior to the binding of polycombs during de novo infection, but only cohesin is required for the genome-wide inhibition of lytic genes. We propose that cohesin is required for the establishment of KSHV latency by initiating the repression of lytic genes following infection, which is an essential step in persistent infection of humans.

Connected Gene Communities Underlie Transcriptional Changes in Cornelia de Lange Syndrome

Cornelia de Lange syndrome (CdLS) is a complex multisystem developmental disorder caused by mutations in cohesin subunits and regulators. While its precise molecular mechanisms are not well defined, they point toward a global deregulation of the transcriptional gene expression program. Cohesin is associated with the boundaries of chromosome domains and with enhancer and promoter regions connecting the three-dimensional genome organization with transcriptional regulation. Here, we show that connected gene communities, structures emerging from the interactions of noncoding regulatory elements and genes in the three-dimensional chromosomal space, provide a molecular explanation for the pathoetiology of CdLS associated with mutations in the cohesin-loading factor NIPBL and the cohesin subunit SMC1A NIPBL and cohesin are important constituents of connected gene communities that are centrally positioned at noncoding regulatory elements. Accordingly, genes deregulated in CdLS are positioned within reach of NIPBL- and cohesin-occupied regions through promoter-promoter interactions. Our findings suggest a dynamic model where NIPBL loads cohesin to connect genes in communities, offering an explanation for the gene expression deregulation in the CdLS.

CHD associated with syndromic diagnoses: peri-operative risk factors and early outcomes

CHD is frequently associated with a genetic syndrome. These syndromes often present specific cardiovascular and non-cardiovascular co-morbidities that confer significant peri-operative risks affecting multiple organ systems. Although surgical outcomes have improved over time, these co-morbidities continue to contribute substantially to poor peri-operative mortality and morbidity outcomes. Peri-operative morbidity may have long-standing ramifications on neurodevelopment and overall health. Recognising the cardiovascular and non-cardiovascular risks associated with specific syndromic diagnoses will facilitate expectant management, early detection of clinical problems, and improved outcomes--for example, the development of syndrome-based protocols for peri-operative evaluation and prophylactic actions may improve outcomes for the more frequently encountered syndromes such as 22q11 deletion syndrome.

Thrombocytopenia and Cornelia de Lange syndrome: Still an enigma?

Cornelia de Lange Syndrome (CdLS) is a rare genetic disorder caused by mutations in the cohesion complex and its regulators. The syndrome is characterized by multiple organ system abnormalities, pre- and post-natal growth retardation and typical facial features. Thrombocytopenia is a reduction in platelet count to <150 × 10(9)  L. It can be caused by congenital or acquired decreased production, increased destruction, or sequestration of platelets. In recent years, several papers reported thrombocytopenia and immune thrombocytopenia in patients affected by CdLS. In 2011, Lambert et al. estimated the risk of idiopathic thrombocytopenia purpura in CdLS patients to be 31-633 times greater than in the general population. We describe the incidence of thrombocytopenia in 127 Italian CdLS patients, identifying patients with transient or persistent thrombocytopenia, but a lower incidence of true idiopathic thrombocytopenic purpura (ITP).

Stage-specific binding profiles of cohesin in resting and activated B lymphocytes suggest a role for cohesin in immunoglobulin class switching and maturation

The immunoglobulin heavy chain locus (Igh) features higher-order chromosomal interactions to facilitate stage-specific assembly of the Ig molecule. Cohesin, a ring-like protein complex required for sister chromatid cohesion, shapes chromosome architecture and chromatin interactions important for transcriptional regulation and often acts together with CTCF. Cohesin is likely involved in B cell activation and Ig class switch recombination. Hence, binding profiles of cohesin in resting mature murine splenic B lymphocytes and at two stages after cell activation were elucidated by chromatin immunoprecipitation and deep sequencing. Comparative genomic analysis revealed cohesin extensively changes its binding to transcriptional control elements after 48 h of stimulation with LPS/IL-4. Cohesin was clearly underrepresented at switch regions regardless of their activation status, suggesting that switch regions need to be cohesin-poor. Specific binding changes of cohesin at B-cell specific gene loci Pax5 and Blimp-1 indicate new cohesin-dependent regulatory pathways. Together with conserved cohesin/CTCF sites at the Igh 3'RR, a prominent cohesin/CTCF binding site was revealed near the 3' end of Cα where PolII localizes to 3' enhancers. Our study shows that cohesin likely regulates B cell activation and maturation, including Ig class switching.