Publications by authors named "Joao Paulo Kitajima"

Article Synopsis
  • Brain development involves the coordinated growth of structures necessary for forming neural circuits, with the corpus callosum being a crucial connection between brain hemispheres.
  • Defects in the growth process, particularly in the development of callosal projection neurons, can lead to syndromic corpus callosum dysgenesis (CCD) and are associated with other conditions like microcephaly.
  • The study identifies WDR47 as a key gene responsible for survival of callosal neurons and highlights its role in mitochondrial and microtubule maintenance, suggesting that mutations in this gene lead to a new neurodevelopmental syndrome involving corpus callosum abnormalities.
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Purpose: This study aims to comprehensively delineate the phenotypic spectrum of ACTL6B-related disorders, previously associated with both autosomal recessive and autosomal dominant neurodevelopmental disorders. Molecularly, the role of the nucleolar protein ACTL6B in contributing to the disease has remained unclear.

Methods: We identified 105 affected individuals, including 39 previously reported cases, and systematically analysed detailed clinical and genetic data for all individuals.

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Accurately calling indels with next-generation sequencing (NGS) data is critical for clinical application. The precisionFDA team collaborated with the U.S.

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  • The authors of the article "Nucleocapsid (N) gene mutations of SARS-CoV-2 can affect real-time RT-PCR diagnostic and impact false-negative results" are requesting to add two individuals, Olivia Teixeira and Maria Cristina Nonato, as co-authors.
  • This request suggests that both individuals contributed to the research and findings presented in the article.
  • The inclusion of these authors may highlight their roles in addressing the implications of genetic mutations in SARS-CoV-2 and improving diagnostic accuracy.
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Chromosomal microarray analysis (CMA) has been recommended and practiced routinely since 2010 both in the USA and Europe as the first-tier cytogenetic test for patients with unexplained neurodevelopmental delay/intellectual disability, autism spectrum disorders, and/or multiple congenital anomalies. However, in Brazil, the use of CMA is still limited, due to its high cost and complexity in integrating the results from both the private and public health systems. Although Brazil has one of the world's largest single-payer public healthcare systems, nearly all patients referred for CMA come from the private sector, resulting in only a small number of CMA studies in Brazilian cohorts.

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Article Synopsis
  • Brazil has experienced high COVID-19 cases and deaths, making Latin America a major pandemic epicenter, with early sustained virus transmission and ongoing gaps in understanding.
  • Researchers analyzed over 17,000 near-complete SARS-CoV-2 genomes from across Brazil and Paraguay, finding multiple viral lineages predominantly imported from Europe before local transmission clusters emerged after November 2020.
  • Effective genomic surveillance has been crucial in tracking the real-time spread of significant variants, such as Gamma (P.1) and Zeta (P.2), and understanding cross-border virus movement into Paraguay.
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Article Synopsis
  • - Brazil became a major COVID-19 epicenter in Latin America by May 2021, experiencing high transmission rates and deaths, but gaps remain in understanding how the virus spreads nationally.
  • - The study analyzes nearly complete SARS-CoV-2 genomes from Brazil and Paraguay, revealing that the initial wave was marked by multiple imported viral lineages mainly from Europe, leading to significant local transmission clusters.
  • - As the pandemic progressed without effective restrictions, Brazil saw the emergence and spread of concerning variants like Gamma and Zeta, highlighting the need for extensive genomic surveillance in South America for better pandemic management and public health strategies.
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The current COVID-19 pandemic demands massive testing by Real-time RT-PCR (Reverse Transcription Polymerase Chain Reaction), which is considered the gold standard diagnostic test for the detection of the SARS-CoV-2 virus. However, the virus continues to evolve with mutations that lead to phenotypic alterations as higher transmissibility, pathogenicity or vaccine evasion. Another big issue are mutations in the annealing sites of primers and probes of RT-PCR diagnostic kits leading to false-negative results.

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Article Synopsis
  • - The SARS-CoV-2 alpha variant (B.1.1.7) emerged in the UK in 2020 and quickly spread throughout Europe, with indications that it circulated in Brazil, particularly in São Paulo.
  • - Phylogenetic analysis of alpha VOC strains in São Paulo from February to August 2021 revealed multiple independent introductions of the variant from both domestic and international sources, along with significant local clusters.
  • - The study emphasizes the importance of ongoing genomic surveillance to monitor emerging SARS-CoV-2 variants amid increasing vaccination efforts.
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The genus Passiflora comprises a large group of plants popularly known as passionfruit, much appreciated for their exotic flowers and edible fruits. The species (∼500) are morphologically variable (e.g.

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: This study aims to demonstrate the possibility of detecting segmental uniparental isodisomy (iUPD) using a next-generation sequencing gene panel by reporting a Leber congenital amaurosis (LCA) case caused by a homozygous pathogenic variant in (c.1022 T > C:p.Leu341Ser) inherited exclusively from the proband's mother.

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Objective: Protein misfolding plays a central role not only in amyotrophic lateral sclerosis (ALS), but also in other conditions, such as frontotemporal dementia (FTD), inclusion body myopathy (hIBM) or Paget's disease of bone. The concept of multisystem proteinopathies (MSP) was created to account for those rare families that segregate at least 2 out of these 4 conditions in the same pedigree. The calcium-dependent phospholipid-binding protein annexin A11 was recently associated to ALS in European pedigrees.

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Purpose: To identify novel genes associated with intellectual disability (ID) in four unrelated families.

Methods: Here, through exome sequencing and international collaboration, we report eight individuals from four unrelated families of diverse geographic origin with biallelic loss-of-function variants in UBE4A.

Results: Eight evaluated individuals presented with syndromic intellectual disability and global developmental delay.

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Here, we present the first complete chromosome-level genome assembly of the smut fungus strain SPL10A, the causal agent of the sourgrass () smut disease. Combining Illumina paired-end and Nanopore long reads, we generated a final assembly composed of 23 chromosomes (22 nuclear and one mitochondrial) with 18,915,934 bp. Gene prediction accomplished using extrinsic evidence from the sugarcane smut fungus originated a total of 6,402 protein-encoding genes.

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Article Synopsis
  • The study aimed to analyze the genetic variations in the survival motor neuron 1 (SMN1) gene among Brazilian patients with spinal muscular atrophy (SMA) and to connect these variants with disease severity.
  • Out of 450 patients, the majority (89.3%) had a common deletion in exon 7, while others had a mix of this deletion and additional point mutations, with certain variants being more prevalent in compound heterozygous cases.
  • The research concluded that specific variants (c.460C>T and c.5C>G) were linked to milder disease forms, and that the copy number of the gene did not consistently predict disease severity among these patients.*
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Introduction: KCNT2 was recently recognized as a gene associated with neurodevelopmental disorder and epilepsy.

Case Report: We present an additional observation of a 16-year-old male patient with a novel de novo KCNT2 likely pathogenic variant and review the five previously reported cases of de novo variants in this gene.

Discussion: Whole exome sequencing identified the missense variant c.

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subsp. , once confined to South America and infecting mainly citrus and coffee plants, has been found to be associated with other hosts and in other geographic regions. We present high-quality draft genome sequences of subsp.

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SCN3A was recently recognized as a gene associated with neurodevelopmental disorder and epilepsy. We present two additional patients with a novel de novo SCN3A pathogenic variant, and a review of all published cases of de novo variants. In one of our patients brain magnetic resonance imaging (MRI) disclosed a severe polymicrogyria and in the other it was normal.

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Members of a paralogous gene family in which variation in one gene is known to cause disease are eight times more likely to also be associated with human disease. Recent studies have elucidated DHX30 and DDX3X as genes for which pathogenic variant alleles are involved in neurodevelopmental disorders. We hypothesized that variants in paralogous genes encoding members of the DExD/H-box RNA helicase superfamily might also underlie developmental delay and/or intellectual disability (DD and/or ID) disease phenotypes.

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The Na/K- ATPase acts as an ion pump maintaining the essential plasma membrane potential in all mammalian cell types, and is essential for many cellular functions. There are four α isoforms (α1, α2, α3 and α4) with distinct expression patterns, kinetic properties and substrate affinity. The α2-isoform is encoded by ATP1A2 and evidence supports its utmost importance in Cl homeostasis in neurons, and in the function of respiratory neurons at birth.

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It has been proposed that copy number variations (CNVs) are associated with increased risk of autism spectrum disorder (ASD) and, in conjunction with other genetic changes, contribute to the heterogeneity of ASD phenotypes. Array comparative genomic hybridization (aCGH) and exome sequencing, together with systems genetics and network analyses, are being used as tools for the study of complex disorders of unknown etiology, especially those characterized by significant genetic and phenotypic heterogeneity. Therefore, to characterize the complex genotype-phenotype relationship, we performed aCGH and sequenced the exomes of two affected siblings with ASD symptoms, dysmorphic features, and intellectual disability, searching for de novo CNVs, as well as for de novo and rare inherited point variations-single nucleotide variants (SNVs) or small insertions and deletions (indels)-with probable functional impacts.

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