Publications by authors named "Luis Seabra"

Aicardi-Goutières syndrome (AGS) is a rare monogenic type I interferonopathy. Janus kinase (JAK) inhibition has emerged as a potential treatment for AGS. RNU7-1 is one of the most recently discovered genes for AGS, and the clinical effects of JAK inhibition in these patients have not been reported.

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Patients heterozygous for germline CBL loss-of-function (LOF) variants can develop myeloid malignancy, autoinflammation, or both, if some or all of their leukocytes become homozygous for these variants through somatic loss of heterozygosity (LOH) via uniparental isodisomy. We observed an upregulation of the inflammatory gene expression signature in whole blood from these patients, mimicking monogenic inborn errors underlying autoinflammation. Remarkably, these patients had constitutively activated monocytes that secreted 10 to 100 times more inflammatory cytokines than those of healthy individuals and CBL LOF heterozygotes without LOH.

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Article Synopsis
  • Hereditary C1q deficiency (C1QDef) is a rare genetic disorder that disrupts the complement system and can cause symptoms similar to systemic lupus erythematosus (SLE).
  • A study of 12 genetically confirmed C1QDef patients showed elevated expression of interferon-stimulated genes and high levels of interferon alpha in their blood and cerebrospinal fluid, indicating significant immune dysfunction.
  • Treatment with Janus-kinase inhibitors had mixed results, with one patient improving while others continued to struggle with their condition, highlighting the complexity of managing C1QDef.
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  • UNC93B1 is a protein involved in signaling for Toll-like receptors, which are important for the immune response.
  • Mutations in UNC93B1 (I317M, G325C, L330R, R466S, and R525P) have been linked to conditions like systemic lupus erythematosus (SLE) and chilblain lupus (CBL), exhibiting both autosomal dominant and recessive inheritance patterns.
  • Different mutations impact the activity of TLR7 and TLR8 differently, suggesting that specific mutations in UNC93B1 lead to varying disease mechanisms for SLE and CBL.
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Primary familial brain calcification (PFBC) is characterized by calcium deposition in the brain, causing progressive movement disorders, psychiatric symptoms, and cognitive decline. PFBC is a heterogeneous disorder currently linked to variants in six different genes, but most patients remain genetically undiagnosed. Here, we identify biallelic NAA60 variants in ten individuals from seven families with autosomal recessive PFBC.

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-related leukoencephalopathy is a new diagnostic entity linked to heterozygous gain-of-function variants in that neuroradiologically show some overlap with the inflammatory microangiopathy Aicardi-Goutières syndrome (AGS). To report a 16-year-old boy harbouring a novel mutation who presented neuroradiological features suggestive of enhanced type I interferon signalling. We describe five years of follow-up and review the current literature on -related leukoencephalopathy.

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Article Synopsis
  • Aicardi-Goutières syndrome (AGS) is an immune-mediated disorder primarily affecting the nervous system, and conventional treatments are largely ineffective.
  • A study on JAK1/2 inhibitors showed significant improvement in systemic symptoms of AGS over a median follow-up of 17 months, although neurological benefits were less clear.
  • The findings highlight the need for better treatment strategies for AGS's neurological symptoms, emphasizing early diagnosis and potential intrathecal drug delivery for improved outcomes.
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  • - Recent discoveries in Northwest Iberia reveal some of the earliest Western European remains of rye, dating back to between the 3rd century and the first half of the 1st century BCE, but their chronological and cultural contexts have not been fully analyzed.
  • - Rye was typically present in archaeological samples alongside spelt and other cereals, likely functioning as a weed in those early agricultural fields, before disappearing for about two centuries.
  • - After its absence, rye reemerged in the 3rd-4th centuries CE as a significant crop, with notable changes in grain size only appearing in a settlement from the 10th-11th century, indicating limited evolution in grain morphology prior to the Medieval period.
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Purpose: STAT2 is both an effector and negative regulator of type I interferon (IFN-I) signalling. We describe the characterization of a novel homozygous missense STAT2 substitution in a patient with a type I interferonopathy.

Methods: Whole-genome sequencing (WGS) was used to identify the genetic basis of disease in a patient with features of enhanced IFN-I signalling.

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Introduction: Juvenile systemic lupus erythematosus (j-SLE) is a rare chronic autoimmune disease affecting multiple organs. Ranging from minor features, such as headache or mild cognitive impairment, to serious and life-threatening presentations, j-neuropsychiatric SLE (j-NPSLE) is a therapeutic challenge. Thus, the diagnosis of NPSLE remains difficult, especially in pediatrics, with no specific biomarker of the disease yet validated.

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Small rural places are largely absent from early medieval written sources, but they were profuse and relevant in regional settlements and economies. Only through archaeological and archaeobotanical investigation is it possible to unveil their structure and productive strategies; however, this kind of investigation is still uncommon in Iberia. Here, the assemblage of fruits/seeds, wood charcoal, and food remains from Senhora do Barrocal (SB) (Sátão, Portugal) will be presented and discussed in order to understand the crop production, processing, and storage.

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Variants in aminoacyl-tRNA synthetases (ARSs) genes are associated to a broad spectrum of human inherited diseases. Patients with defective PheRS, encoded by FARSA and FARSB, display brain abnormalities, interstitial lung disease and facial dysmorphism. We investigated four children from two unrelated consanguineous families carrying two missense homozygous variants in FARSA with significantly reduced PheRS-mediated aminoacylation activity.

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Mitochondrial DNA (mtDNA) has been suggested to drive immune system activation, but the induction of interferon signaling by mtDNA has not been demonstrated in a Mendelian mitochondrial disease. We initially ascertained two patients, one with a purely neurological phenotype and one with features suggestive of systemic sclerosis in a syndromic context, and found them both to demonstrate enhanced interferon-stimulated gene (ISG) expression in blood. We determined each to harbor a previously described de novo dominant-negative heterozygous mutation in ATAD3A, encoding ATPase family AAA domain-containing protein 3A (ATAD3A).

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Aim: Coats plus syndrome (CP) is a rare autosomal recessive disorder, characterised by retinal telangiectasia exudates (Coats disease), leukodystrophy, distinctive intracranial calcification and cysts, as well as extra-neurological features including abnormal vasculature of the gastrointestinal tract, portal hypertension and osteopenia with a tendency to fractures. CP most frequently occurs due to loss-of-function mutations in CTC1. The encoded protein CTC1 constitutes part of the CST (CTC1-STN1-TEN1) complex, and three patients have been described with CP due to biallelic mutations in STN1.

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Whilst upregulation of type I interferon (IFN) signaling is common across the type I interferonopathies (T1Is), central nervous system (CNS) involvement varies between these disorders, the basis of which remains unclear. We collected cerebrospinal fluid (CSF) and serum from patients with Aicardi-Goutières syndrome (AGS), STING-associated vasculopathy with onset in infancy (SAVI), presumed monogenic T1Is (pT1I), childhood systemic lupus erythematosus with neuropsychiatric features (nSLE), non-IFN-related autoinflammation (AI) and non-inflammatory hydrocephalus (as controls). We measured IFN-alpha protein using digital ELISA.

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Inappropriate stimulation or defective negative regulation of the type I interferon response can lead to autoinflammation. In genetically uncharacterized cases of the type I interferonopathy Aicardi-Goutières syndrome, we identified biallelic mutations in LSM11 and RNU7-1, which encode components of the replication-dependent histone pre-mRNA-processing complex. Mutations were associated with the misprocessing of canonical histone transcripts and a disturbance of linker histone stoichiometry.

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Background: Gain-of-function mutations in STING1 underlie a type I interferonopathy termed SAVI (STING-associated vasculopathy with onset in infancy). This severe disease is variably characterized by early-onset systemic inflammation, skin vasculopathy, and interstitial lung disease (ILD).

Objective: To describe a cohort of patients with SAVI.

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Article Synopsis
  • Biallelic mutations in the SNORD118 gene are linked to a neurological condition called leukoencephalopathy with calcifications and cysts (LCC), affecting individuals' brains and leading to a range of symptoms.
  • A study identified 64 patients with LCC, showcasing a wide age range at disease onset and highlighting that most were compound heterozygotes for mutations in SNORD118, with many involving seven key nucleotides crucial for a specific RNA interaction.
  • The findings indicate that LCC is likely caused by a combination of severe and milder mutations impacting RNA processing, but there is no clear link between specific mutations and the age at which symptoms appear.
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Heterozygous missense mutations in coatomer protein subunit α, COPA, cause a syndrome overlapping clinically with type I IFN-mediated disease due to gain-of-function in STING, a key adaptor of IFN signaling. Recently, increased levels of IFN-stimulated genes (ISGs) were described in COPA syndrome. However, the link between COPA mutations and IFN signaling is unknown.

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We report the clinical and molecular characterization of a novel biallelic mutation in the gene leading to an autosomal recessive form of childhood onset leukoencephalopathy in a consanguineous family. The female child experienced acute encephalopathy at the age of 2 years, followed by spasticity and loss of all achieved milestones over 6 months. Her elder brother presented with encephalopathy at 4 years of age, with a subsequent loss of all achieved milestones over 8 months.

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  • IFIH1 gain-of-function mutations lead to a type I interferonopathy, causing various autoinflammatory conditions like Aicardi-Goutières syndrome and Singleton Merten syndrome.
  • A study identified 74 individuals from 51 families with 27 likely pathogenic mutations in IFIH1, revealing that some adults (13.5%) showed no symptoms despite carrying the mutation.
  • All mutations resulted in heightened type I interferon signaling, with certain variants incorrectly predicted as benign, indicating a complex relationship between the genotype and the expression of symptoms.
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  • Mutations in adenosine deaminases acting on RNA can lead to a range of neurological disorders and heightened type I interferon signaling, along with non-neurological issues like autoimmune problems.
  • This study focuses on three patients who, due to genetic mutations, developed calcifying cardiac valve disease during late childhood, leading to severe heart issues including biventricular failure.
  • The findings suggest that type I interferonopathies can cause serious cardiac complications in childhood, emphasizing the need for regular echocardiogram screenings to catch potential heart issues early.
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  • - The study examines two subtypes of juvenile idiopathic inflammatory myopathy (JIIM) associated with anti-MDA5 autoantibodies, finding they have distinct clinical features compared to other JIIM types, such as more arthritis and skin ulcerations but less severe muscle involvement.
  • - Researchers analyzed 64 patients from French pediatric rheumatology centers, using muscle biopsies and measuring IFNα serum protein levels to assess disease status and treatment outcomes.
  • - The findings indicate that systemic IFNα plays a significant role in the pathology of JIIM with anti-MDA5 autoantibodies, suggesting it could be a target for treatment in severe cases.
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