Publications by authors named "Igor Stevanovski"

Objective: We aim to describe and characterize two unrelated Spanish families suffering from an autosomal dominant autophagic vacuolar myopathy caused by repeat expansions in PLIN4.

Methods: We evaluated the clinical phenotype and muscle imaging, and performed a genetic workup that included exome sequencing, muscle RNAseq, and long-read genome sequencing. Muscle pathology was assessed by means of histochemistry, electron microscopy, PLIN4, p62, LC3, and NBR1 immunofluorescence and/or western blotting.

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Aggregation-prone polyglycine-containing proteins produced from expanded GGC repeats are implicated in an emerging family of neurodegenerative disorders. In this study, we showed that polyglycine itself forms aggregates that incorporate endogenous glycine-rich proteins, including FAM98B, a component of the transfer RNA (tRNA) ligase complex (tRNA-LC) that harbors the most glycine-rich sequence in the human proteome. Through this glycine-rich intrinsically disordered region (IDR), polyglycine sequesters and depletes the tRNA-LC, disrupting tRNA processing.

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Objective: The hereditary spastic-ataxia spectrum disorders are a group of disabling neurological diseases. The traditional genetic testing pathway is complex, multistep and leaves many cases unsolved. We aim to streamline and improve this process using long-read sequencing.

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Primary liver cancer is an increasing problem worldwide and is associated with significant mortality. A popular method of modeling liver cancer in mice is plasmid hydrodynamic tail vein injection (HTVI). However, plasmid-HTVI models rarely recapitulate the chronic liver injury which precedes the development of most human liver cancer.

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Article Synopsis
  • Oculopharyngodistal myopathy (OPDM) is a genetic muscle disease that causes drooping eyelids, trouble swallowing, and weakness in the arms and legs.
  • Recent research found repeating sequences in a gene called ABCD3 in people with OPDM from European backgrounds, while similar repeats were only discovered in certain Asian groups before.
  • These long repeats in the ABCD3 gene might play a role in the muscle problems seen in OPDM, suggesting a link between these repeats and the weakness that affects patients.
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  • The study investigates the factors affecting the expansion of tandem repeats, focusing on the FGF14 (GAA)·(TTC) repeat locus in a large sample of 2,530 individuals through advanced sequencing techniques.
  • Researchers discovered a prevalent 5'-flanking variant present in over 70% of alleles, which is linked to nonpathogenic alleles and the ancestral lineage of this genetic marker.
  • This common variant is associated with greater stability of the tandem repeat during inheritance and improved accessibility of chromatin, suggesting a role in preventing pathological expansion.
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Background: Loss-of-function variants in MME (membrane metalloendopeptidase) are a known cause of recessive Charcot-Marie-Tooth Neuropathy (CMT). A deep intronic variant, MME c.1188+428A>G (NM_000902.

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The expression of genes encompasses their transcription into mRNA followed by translation into protein. In recent years, next-generation sequencing and mass spectrometry methods have profiled DNA, RNA and protein abundance in cells. However, there are currently no reference standards that are compatible across these genomic, transcriptomic and proteomic methods, and provide an integrated measure of gene expression.

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Purpose: Genome sequencing (GS)-specific diagnostic rates in prospective tightly ascertained exome sequencing (ES)-negative intellectual disability (ID) cohorts have not been reported extensively.

Methods: ES, GS, epigenetic signatures, and long-read sequencing diagnoses were assessed in 74 trios with at least moderate ID.

Results: The ES diagnostic yield was 42 of 74 (57%).

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Indigenous Australians harbour rich and unique genomic diversity. However, Aboriginal and Torres Strait Islander ancestries are historically under-represented in genomics research and almost completely missing from reference datasets. Addressing this representation gap is critical, both to advance our understanding of global human genomic diversity and as a prerequisite for ensuring equitable outcomes in genomic medicine.

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  • Cerebellar ataxia, neuropathy and vestibular areflexia syndrome is a progressive neurological disorder linked to genetic mutations in a specific gene, which has shown significant variability in its genetic makeup.
  • A study screened 242 Australasian patients with neurological diseases to find correlations between these genetic expansions and the disorder, discovering known pathogenic expansions in 15.3% of the cases.
  • Additionally, researchers identified previously unknown genetic repeat motifs and suggested the use of enhanced sequencing techniques to better understand the complex patterns of these genetic expansions.
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  • - Cerebellar ataxia, neuropathy and vestibular areflexia syndrome (CANVAS) is a rare neurodegenerative disease linked to genetic mutations, particularly biallelic AAGGG repeat expansions in the RFC1 gene.
  • - A study analyzed whole genome sequencing data from almost 10,000 individuals and discovered three new repeat variations related to CANVAS, alongside confirming the pathogenic nature of larger AAAGG expansions.
  • - The research highlights the need for careful genetic testing in CANVAS patients, especially for those carrying specific repeat configurations, to ensure accurate diagnosis and family counseling.
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Autosomal dominant polycystic kidney disease (ADPKD) is the most common monogenic cause of kidney failure and is primarily associated with PKD1 or PKD2. Approximately 10% of patients remain undiagnosed after standard genetic testing. We aimed to utilise short and long-read genome sequencing and RNA studies to investigate undiagnosed families.

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Objective: Duchenne muscular dystrophy (DMD) is caused by pathogenic variants in the dystrophin gene (). Hypermethylated CGG expansions within 5' UTR are associated with an intellectual development disorder. Here, we demonstrate the diagnostic utility of genomic short-read sequencing (SRS) and transcriptome sequencing to identify a novel structural variant (SV) and a CGG expansion in a patient with DMD for whom conventional diagnostic testing failed to yield a genetic diagnosis.

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Library adaptors are short oligonucleotides that are attached to RNA and DNA samples in preparation for next-generation sequencing (NGS). Adaptors can also include additional functional elements, such as sample indexes and unique molecular identifiers, to improve library analysis. Here, we describe Control Library Adaptors, termed CAPTORs, that measure the accuracy and reliability of NGS.

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Our understanding of the molecular pathology of posttraumatic stress disorder (PTSD) is evolving due to advances in sequencing technologies. With the recent emergence of Oxford Nanopore direct RNA-seq (dRNA-seq), it is now also possible to interrogate diverse RNA modifications, collectively known as the "epitranscriptome.".

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More than 50 neurological and neuromuscular diseases are caused by short tandem repeat (STR) expansions, with 37 different genes implicated to date. We describe the use of programmable targeted long-read sequencing with Oxford Nanopore's ReadUntil function for parallel genotyping of all known neuropathogenic STRs in a single assay. Our approach enables accurate, haplotype-resolved assembly and DNA methylation profiling of STR sites, from a list of predetermined candidates.

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Biallelic mutations in sorbitol dehydrogenase (SORD) have been recently identified as a common cause of recessive axonal Charcot-Marie-Tooth neuropathy (CMT2). We aimed to assess a novel long-read sequencing approach to overcome current limitations in SORD neuropathy diagnostics due to the SORD2P pseudogene and the phasing of biallelic mutations in recessive disease. We conducted a screen of our Australian whole exome sequencing (WES) CMT cohort to identify individuals with homozygous or compound heterozygous SORD variants.

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Circulating tumor DNA (ctDNA) sequencing is being rapidly adopted in precision oncology, but the accuracy, sensitivity and reproducibility of ctDNA assays is poorly understood. Here we report the findings of a multi-site, cross-platform evaluation of the analytical performance of five industry-leading ctDNA assays. We evaluated each stage of the ctDNA sequencing workflow with simulations, synthetic DNA spike-in experiments and proficiency testing on standardized, cell-line-derived reference samples.

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Accumulating evidence supports the high prevalence of co-infections among Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) patients, and their potential to worsen the clinical outcome of COVID-19. However, there are few data on Southern Hemisphere populations, and most studies to date have investigated a narrow spectrum of viruses using targeted qRT-PCR. Here we assessed respiratory viral co-infections among SARS-CoV-2 patients in Australia, through respiratory virome characterization.

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Viral whole-genome sequencing (WGS) provides critical insight into the transmission and evolution of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Long-read sequencing devices from Oxford Nanopore Technologies (ONT) promise significant improvements in turnaround time, portability and cost, compared to established short-read sequencing platforms for viral WGS (e.g.

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The advent of portable nanopore sequencing devices has enabled DNA and RNA sequencing to be performed in the field or the clinic. However, advances in in situ genomics require parallel development of portable, offline solutions for the computational analysis of sequencing data. Here we introduce Genopo, a mobile toolkit for nanopore sequencing analysis.

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