Rare genetic variants involved in multisystem inflammatory syndrome in children: a multicenter Brazilian cohort study

IntroductionDespite the existing data on the Multisystem Inflammatory Syndrome in Children (MIS-C), the factors that determine these patients evolution remain elusive. Answers may lie, at least in part, in genetics. It is currently under investigation that MIS-C patients may have an underlying innate error of immunity (IEI), whether of monogenic, digenic, or even oligogenic origin.MethodsTo further investigate this hypothesis, 30 patients with MIS-C were submitted to whole exome sequencing. ResultsAnalyses of genes associated with MIS-C, MIS-A, severe covid-19, and Kawasaki disease identified twenty-nine patients with rare potentially damaging variants (50 variants were identified in 38 different genes), including those previously described in IFNA21 and IFIH1 genes, new variants in genes previously described in MIS-C patients (KMT2D, CFB, and PRF1), and variants in genes newly associated to MIS-C such as APOL1, TNFRSF13B, and G6PD. In addition, gene ontology enrichment pointed to the involvement of thirteen major pathways, including complement system, hematopoiesis, immune system development, and type II interferon signaling, that were not yet reported in MIS-C.DiscussionThese data strongly indicate that different gene families may favor MIS- C development. Larger cohort studies with healthy controls and other omics approaches, such as proteomics and RNAseq, will be precious to better understanding the disease dynamics

Repercussions of the COVID-19 pandemic on preventive health services in Brazil

IntroductionThe increasing burden of non-communicable diseases and limited public financing are major challenges facing health care systems in Latin America. Although COVID-19 severely impacted the Brazilian health care system, it is crucial to further characterize the degree of disruption caused to public health efforts, in order to address and manage long term effects of this pandemic. We therefore quantified the demand for preventive and treatment services from the Brazilian Unified Health System (Sistema Único de Saúde/SUS) in 2020 to evaluate potential repercussions of COVID-19 in this setting.MethodsUsing the SUS database, we compared preventative and treatment services rendered in 2020 to the same services rendered from 2017 to 19. We also evaluated the frequency of respiratory infection (RI) diagnoses during the pandemic, relative to the preceding years.ResultsCompared to 2017-19, in 2020 non-urgent medical appointments decreased 1.4-fold (p = 0.0017), dental consultations 2.8-fold (p = 0.05), and immunization coverage 1.5 fold (p = 0.0005). The number of RI visits to SUS ambulatory care units in 2020 was 4.2 times higher than in preceding years (p = 0.0014), with a peak of 280,898 diagnoses in July 2020.ConclusionThe COVID-19 pandemic appears to have led to a dramatic decline in preventative and treatment services provided by SUS to the Brazilian population. Our findings may aid decision-makers in formulating policies to increase the availability of outpatient services in the aftermath of the pandemic. Counter measures will be critical to avoid a resurgence in vaccine-preventable diseases and complications stemming from non-communicable, chronic health conditions

Genetic screening in a Brazilian cohort with inborn errors of immunity

Abstract Background Inherited genetic defects in immune system-related genes can result in Inborn Errors of Immunity (IEI), also known as Primary Immunodeficiencies (PID). Diagnosis of IEI disorders is challenging due to overlapping clinical manifestations. Accurate identification of disease-causing germline variants is crucial for appropriate treatment, prognosis, and genetic counseling. However, genetic sequencing is challenging in low-income countries like Brazil. This study aimed to perform genetic screening on patients treated within Brazil's public Unified Health System to identify candidate genetic variants associated with the patient’s phenotype. Methods Thirteen singleton unrelated patients from three hospitals in Rio de Janeiro were enrolled in this study. Genomic DNA was extracted from the peripheral blood lymphocytes of each patient, and whole exome sequencing (WES) analyses were conducted using Illumina NextSeq. Germline genetic variants in IEI-related genes were prioritized using a computational framework considering their molecular consequence in coding regions; minor allele frequency ≤ 0.01; pathogenicity classification based on American College of Medical Genetics and Genomics and the Association for Molecular Pathology (ACMG/AMP) guidelines gathered from the VarSome clinical database; and IEI-related phenotype using the Franklin tool. The genes classification into IEI categories follows internationally recognized guidelines informed by the International Union of Immunological Societies Expert Committee. Additional methods for confirmation of the variant included Sanger sequencing, phasing analysis, and splice site prediction. Results A total of 16 disease-causing variants in nine genes, encompassing six different IEI categories, were identified. X-Linked Agammaglobulinemia, caused by BTK variations, emerged as the most prevalent IEI disorder in the cohort. However, pathogenic and likely pathogenic variants were also reported in other known IEI-related genes, namely CD40LG, CARD11, WAS, CYBB, C6, and LRBA. Interestingly, two patients with suspected IEI exhibited pathogenic variants in non-IEI-related genes, ABCA12 and SLC25A13, potentially explaining their phenotypes. Conclusions Genetic screening through WES enabled the detection of potentially harmful variants associated with IEI disorders. These findings contribute to a better understanding of patients' clinical manifestations by elucidating the genetic basis underlying their phenotypes

Data table 3 - Detailed information of the rare and Pathogenic/Likely pathogenic variants found in the cohort

This work aims (i) to make available genomic data generated from the whole-exome sequencing (WES) of Brazilian patients' suspicion of inborn error of immunity (IEI) without genetic diagnosis; (ii) to improve the diagnostic yield of monogenic disorders by providing a clinically relevant dataset; and (iii) to provide high-throughput data with exploitable potential to gain insights about the genomic population structure of the Brazilians.  We sequenced genomic DNA from twenty unrelated patients treated at four different hospitals in the state of Rio de Janeiro, Brazil. Half of the patients were male with mean ages of 9±3 while females were 12±10  years old. WES were conducted through Illumina NextSeq platform and achieved 90% of the genetic basis coverage by >30 reads. More than 80% of the sequencing reads were uniquely mapped to the reference genome. Each sample had an average of 20,274 variants, being 114 classified as rare pathogenic or likely pathogenic according to ACMG guidelines. Overall, the access to clinical exome sequencing data is limited, challenging exploratory analyses and the understanding of genetic mechanisms underlying disorders. Thus, by making these data available, we foresee increasing the number of WES data from Brazilians despite contributing to the study of  monogenic IEI-disorders. </p

Data table 2 - Overview of the sequencing metrics

This work aims (i) to make available genomic data generated from the whole-exome sequencing (WES) of Brazilian patients' suspicion of inborn error of immunity (IEI) without genetic diagnosis; (ii) to improve the diagnostic yield of monogenic disorders by providing a clinically relevant dataset; and (iii) to provide high-throughput data with exploitable potential to gain insights about the genomic population structure of the Brazilians.  We sequenced genomic DNA from twenty unrelated patients treated at four different hospitals in the state of Rio de Janeiro, Brazil. Half of the patients were male with mean ages of 9±3 while females were 12±10  years old. WES were conducted through Illumina NextSeq platform and achieved 90% of the genetic basis coverage by >30 reads. More than 80% of the sequencing reads were uniquely mapped to the reference genome. Each sample had an average of 20,274 variants, being 114 classified as rare pathogenic or likely pathogenic according to ACMG guidelines. Overall, the access to clinical exome sequencing data is limited, challenging exploratory analyses and the understanding of genetic mechanisms underlying disorders. Thus, by making these data available, we foresee increasing the number of WES data from Brazilians despite contributing to the study of  monogenic IEI-disorders. </p

Data table 1 - Demographic characteristics of the cohort

This work aims (i) to make available genomic data generated from the whole-exome sequencing (WES) of Brazilian patients' suspicion of inborn error of immunity (IEI) without genetic diagnosis; (ii) to improve the diagnostic yield of monogenic disorders by providing a clinically relevant dataset; and (iii) to provide high-throughput data with exploitable potential to gain insights about the genomic population structure of the Brazilians.  We sequenced genomic DNA from twenty unrelated patients treated at four different hospitals in the state of Rio de Janeiro, Brazil. Half of the patients were male with mean ages of 9±3 while females were 12±10  years old. WES were conducted through Illumina NextSeq platform and achieved 90% of the genetic basis coverage by >30 reads. More than 80% of the sequencing reads were uniquely mapped to the reference genome. Each sample had an average of 20,274 variants, being 114 classified as rare pathogenic or likely pathogenic according to ACMG guidelines. Overall, the access to clinical exome sequencing data is limited, challenging exploratory analyses and the understanding of genetic mechanisms underlying disorders. Thus, by making these data available, we foresee increasing the number of WES data from Brazilians despite contributing to the study of  monogenic IEI-disorders. </p

Anthropometric Parameters of Children with Congenital Zika Virus Exposure in the First Three Years of Life

Little is known about the impact of congenital Zika virus (ZIKV) exposure on growth in the first years of life. In this prospective cohort study,201 ZIKV antenatally-exposed children were followed at a tertiary referral center in Rio de Janeiro, Brazil. Eighty-seven were classified as congenital Zika syndrome (CZS) patients and 114 as not congenital Zika syndrome (NCZS); growth parameters were described and compared between groups and with WHO standard growth curves. Thirty-four (39%) newborns with CZS and seven (6%) NCZS were small for gestational age (p p p p < 0.01). Between 25 and 36 months of age, more than 50% of the 70 evaluated CZS children were below weight and height limits; 36 (37.1%) were below the W/H cut-off. Gastrostomy was performed in 23 (26%) children with CZS. During the first three years of life, CZS patients had severe and early growth deficits, while growth of NCZS children was normal by WHO standards

Prevalence of IgG Autoantibodies against GD3 Ganglioside in Acute Zika Virus Infection

Zika virus (ZIKV) disease has become a global health emergency with devastating effects on public health. Recent evidences implicate the virus as an emergent neuropathological agent promoting serious pathologies of the human nervous system, that include destructive and malformation consequences such as development of ocular and fetal brain lesions, microcephaly in neonates, and Guillain–Barré syndrome (GBS) in adults. These neurological disorders of both central and peripheral nervous systems are thought to be associated to the neurotropic properties of the virus that has ability to infect neural stem cells as well as peripheral neurons, a hallmark of its pathogenicity. The presence of autoantibodies against gangliosides plays a pivotal role in the etiogenesis of GBS and a variety of neurological disorders. Gangliosides are a class of galactose-containing cerebrosides mainly expressed in nervous system tissues playing a critical role in the physiology of neural cells and neurogenesis. Herein, our findings indicate that patients at acute phase of ZIKV infection without any neurological signs show increased levels of IgG autoantibody against GD3 gangliosides, a class of glycolipid found to be highly expressed in neural stem cell acting in the maintenance of their self-renewal cellular capacity. It is possible that a pathological threshold of these antibodies is only acquired in secondary or subsequent infections. In the light of these evidences, we propose that the target of GD3 by autoimmune responses may possibly has an effect in the neuropathy and neurogenesis disorder seen during ZIKV infection

Obesity Induces an Impaired Placental Antiviral Immune Response in Pregnant Women Infected with Zika Virus

Obesity is increasing in incidence worldwide, especially in women, which can affect the outcome of pregnancy. During this period, viral infections represent a risk to the mother, the placental unit, and the fetus. The Zika virus (ZIKV) outbreak in Brazil has been the cause of congenital Zika syndrome (CZS), with devastating consequences such as microcephaly in newborns. Herein, we analyzed the impact of maternal overweight/obesity on the antiviral factors’ expression in the placental tissue of Zika-infected mothers. We accessed placentas from women with and without obesity from 34 public health units (São Paulo) and from Zika-infected mothers with and without obesity from the Clinical Cohort Study of ZIKV pregnant women (Rio de Janeiro, Brazil). We first verified that obesity, without infection, did not alter the constitutive transcriptional expression of antiviral factors or IFN type I/III expression. Interestingly, obesity, when associated with ZIKV infection, showed a decreased transcriptional expression of RIG-I and IFIH1 (MDA-5 protein precursor gene). At the protein level, we also verified a decreased RIG-I and IRF-3 expression in the decidual placenta from the Zika-infected obese group, regardless of microcephaly. This finding shows, for the first time, that obesity associated with ZIKV infection leads to an impaired type I IFN downstream signaling pathway in the maternal–fetal interface