Genetic Etiology of Left-Sided Obstructive Heart Lesions: A Story in Development.

Congenital heart disease is the most common congenital defect observed in newborns. Within the spectrum of congenital heart disease are left-sided obstructive lesions (LSOLs), which include hypoplastic left heart syndrome, aortic stenosis, bicuspid aortic valve, coarctation of the aorta, and interrupted aortic arch. These defects can arise in isolation or as a component of a defined syndrome; however, nonsyndromic defects are often observed in multiple family members and associated with high sibling recurrence risk. This clear evidence for a heritable basis has driven a lengthy search for disease-causing variants that has uncovered both rare and common variants in genes that, when perturbed in cardiac development, can result in LSOLs. Despite advancements in genetic sequencing platforms and broadening use of exome sequencing, the currently accepted LSOL-associated genes explain only 10% to 20% of patients. Further, the combinatorial effects of common and rare variants as a cause of LSOLs are emerging. In this review, we highlight the genes and variants associated with the different LSOLs and discuss the strengths and weaknesses of the present genetic associations. Furthermore, we discuss the research avenues needed to bridge the gaps in our current understanding of the genetic basis of nonsyndromic congenital heart disease.

Nanopore Sequencing in a Clinical Routine Laboratory: Challenges and Opportunities.

BACKGROUND: About forty-five years ago the advent of Sanger sequencing (Sanger and Coulson 1975) was revolutionary as it allowed deciphering of complete genome sequences. A second revolution came when next-generation sequencing (NGS) technologies accelerated and cheapened genome sequencing. Recently, third generation/longread sequencing methods have appeared, which can directly detect epigenetic modifications on native DNA and allow whole-transcript sequencing without the need for assembly. Nanopore sequencing is one of these third-generation approaches, enabling a single molecule of DNA or RNA to be sequenced in real-time without the need for PCR amplification or chemical labelling of the sample. It works by monitoring changes to an electrical current as nucleic acids are passed through protein or synthetic nanopores. METHODS: A literature search was performed in order to collect and summarize current information about the methodological aspects of nanopore sequencing as well as some application examples. RESULTS: The review describes concisely and comprehensibly the technical aspects of nanopore sequencing and stresses the advantages and disadvantages of this technique thereby also giving examples of their potential applications in the clinical routine laboratory as are rapid identification of viral pathogens, monitoring Ebola, environmental and food safety monitoring, human and plant genome sequencing, monitoring of antibiotic resistance, and other applications. CONCLUSIONS: It is a useful incitation for such ones being permanently in search of upgrading their laboratory.

At the forefront of the sequencing revolution-notes from the RNGS19 conference.

Herein we present a meeting report on the third edition of the 'Revolutionizing Next-Generation Sequencing' conference, organized by the Flemish life-science research institute VIB and held at Antwerp, Belgium, 25-26 March 2019.

Renal genetics in Australia: Kidney medicine in the genomic age.

There have been few new therapies for patients with chronic kidney disease in the last decade. However, the management of patients affected by genetic kidney disease is rapidly evolving. Inherited or genetic kidney disease affects around 10% of adults with end-stage kidney disease and up to 70% of children with early onset kidney disease. Advances in next-generation sequencing have enabled rapid and cost-effective sequencing of large amounts of DNA. Next-generation sequencing-based diagnostic tests now enable identification of a monogenic cause in around 20% of patients with early-onset chronic kidney disease. A definitive diagnosis through genomic testing may negate the need for prolonged diagnostic investigations and surveillance, facilitate reproductive planning and provide accurate counselling for at-risk relatives. Genomics has allowed the better understanding of disease pathogenesis, providing prognostic information and facilitating development of targeted treatments for patients with inherited or genetic kidney disease. Although genomic testing is becoming more readily available, there are many challenges to implementation in clinical practice. Multidisciplinary renal genetics clinics serve as a model of how some of these challenges may be overcome. Such clinics are already well established in most parts of Australia, with more to follow in future. With the rapid pace of new technology and gene discovery, collaboration between expert clinicians, laboratory and research scientists is of increasing importance to maximize benefits to patients and health-care systems.

Advances in Sequencing Technologies for Understanding Hereditary Ataxias: A Review.

IMPORTANCE: The hereditary progressive ataxias comprise genetic disorders that affect the cerebellum and its connections. Even though these diseases historically have been among the first familial disorders of the nervous system to have been recognized, progress in the field has been challenging because of the large number of ataxic genetic syndromes, many of which overlap in their clinical features. OBSERVATIONS: We have taken a historical approach to demonstrate how our knowledge of the genetic basis of ataxic disorders has come about by novel techniques in gene sequencing and bioinformatics. Furthermore, we show that the genes implicated in ataxia, although seemingly unrelated, appear to encode for proteins that interact with each other in connected functional modules. CONCLUSIONS AND RELEVANCE: It has taken approximately 150 years for neurologists to comprehensively unravel the genetic diversity of ataxias. There has been an explosion in our understanding of their molecular basis with the arrival of next-generation sequencing and computer-driven bioinformatics; this in turn has made hereditary ataxias an especially well-developed model group of diseases for gaining insights at a systems level into genes and cellular pathways that result in neurodegeneration.

Revolution of nephrology research by deep sequencing: ChIP-seq and RNA-seq.

The recent and rapid advent of next-generation sequencing (NGS) has made this technology broadly available not only to researchers in various molecular and cellular biology fields but also to those in kidney disease. In this paper, we describe the usage of ChIP-seq (chromatin immunoprecipitation with sequencing) and RNA-seq for sample preparation and interpretation of raw data in the investigation of biological phenomenon in renal diseases. ChIP-seq identifies genome-wide transcriptional DNA-binding sites as well as histone modifications, which are known to regulate gene expression, in the intragenic as well as in the intergenic regions. With regard to RNA-seq, this process analyzes not only the expression level of mRNA but also splicing variants, non-coding RNA, and microRNA on a genome-wide scale. The combination of ChIP-seq and RNA-seq allows the clarification of novel transcriptional mechanisms, which have important roles in various kinds of diseases, including chronic kidney disease. The rapid development of these techniques requires an update on the latest information and methods of NGS. In this review, we highlight the merits and characteristics of ChIP-seq and RNA-seq and discuss the use of the genome-wide analysis in kidney disease.

[Molecular genetics and gene analysis of hereditary spastic paraplegia].

Hereditary spastic paraplegia (HSP) is a neurodegenerative disorder which is characterized by spasticity of the leg. HSP is a clinically and genetically heterogeneous disorder. Mutations were detected in about 60% of autosomal dominant HSP patients. SPG4 is the most common form of autosomal dominant HSP worldwide. In autosomal recessive HSP patients, we detected mutations in about 40% using exome sequencing. Causes of autosomal recessive HSP are more heterogeneous than those of autosomal dominant HSP. We have to consider leukodystrophies/leukoencephalopathies, motor neuron diseases, spinocerebellar degenerations, or various metabolic diseases as differential diagnosis of complicated HSP. X-linked HSP or HSP with mitochondorial inheritance are rare. Further work on familial patients would lead to identify novel causative genes, which helps to understand pathophysiology of HSP and the nature of corticospinal tract and establish disease modifying therapy. Mutation detection rate for sporadic HSP is low at the moment, and molecular delineation of sporadic HSP is expected in the future.

Applications of nanotechnology, next generation sequencing and microarrays in biomedical research.

Next-generation sequencing technologies, microarrays and advances in bio nanotechnology have had an enormous impact on research within a short time frame. This impact appears certain to increase further as many biomedical institutions are now acquiring these prevailing new technologies. Beyond conventional sampling of genome content, wide-ranging applications are rapidly evolving for next-generation sequencing, microarrays and nanotechnology. To date, these technologies have been applied in a variety of contexts, including whole-genome sequencing, targeted re sequencing and discovery of transcription factor binding sites, noncoding RNA expression profiling and molecular diagnostics. This paper thus discusses current applications of nanotechnology, next-generation sequencing technologies and microarrays in biomedical research and highlights the transforming potential these technologies offer.

[The place of functional genomics in oncological research]. / A funkcionális genomikai eszköztár szerepe az onkológiai kutatásokban.

The 1000 genomes project changed the way how we see the human genome. The rapid development of the deep sequencing technologies is raising several practical questions, and the way how we answer these questions will affect deeply the future of the oncological reseach in Hungary. In our manuscript we give a short overview of the results of the 1000 genomes project and we present the place of the functional genomic investigations between other genomic tools. Based on the recent development in the field we summarize the challenges that have to be addressed in the next couple of years.

Two decades of Molecular Ecology: where are we and where are we heading?

The twentieth anniversary of the journal Molecular Ecology was celebrated with a symposium on the current state and the future directions of the field. The event, organized by Tim Vines and Loren Rieseberg, took place on the opening day of the First Joint Congress on Evolutionary Biology organized by the American Society of Naturalists (ASN), the Canadian Society for Ecology and Evolution (CSEE), the European Society for Evolutionary Biology (ESEB), the Society for the Study of Evolution (SSE) and the Society of Systematic Biologists (SSB) in Ottawa (Canada) from 6­10 July 2012. The get together of these five societies created a truly international and exciting "Evolution conference" and the ideal framework for the Molecular Ecology symposium. Its thirteen talks were grouped into the five different subject areas of the journal: Speciation and Hybridization; Landscape Genetics, Phylogeography and Conservation; Ecological Genomics and Molecular Adaptation; Kinship, Parentage and Behaviour; Ecological Interactions. Each session was followed by a panel discussion on the future direction of the subfield. That more than 300 colleagues registered for this special symposium illustrates the broad interest in, and appreciation of, molecular ecology ­ both the field and the journal.

Highlights from the 7th European meeting on molecular diagnostics.

This report presents the highlights of the 7th European Meeting on Molecular Diagnostics held in Scheveningen, The Hague, The Netherlands, 12-14 October 2011. The areas covered included molecular diagnostics applications in medical microbiology, virology, pathology, hemato-oncology, clinical genetics and forensics. Novel real-time amplification approaches, novel diagnostic applications and new technologies, such as next-generation sequencing, PCR electrospray-ionization TOF mass spectrometry and techniques based on the detection of proteins or other molecules, were discussed. Furthermore, diagnostic companies presented their future visions for molecular diagnostics in human healthcare.

Between candidate genes and whole genomes: time for alternative approaches in blood pressure genetics.

Blood pressure has a significant genetic component, but less than 3% of the observed variance has been attributed to genetic variants identified to date. Candidate gene studies of rare, monogenic hypertensive syndromes have conclusively implicated several genes altering renal sodium balance, and studies of essential hypertension have inconsistently implicated over 50 genes in pathways affecting renal sodium balance and other functions. Genome-wide linkage scans have replicated numerous quantitative trait loci throughout the genome, and over 50 single nucleotide polymorphisms (SNPs) have been replicated in multiple genome-wide association studies. These studies provide considerable evidence that epistasis and other interactions play a role in the genetic architecture of blood pressure regulation, but candidate gene studies have limited scope to test for epistasis, and genome-wide studies have low power for both main effects and interactions. This review summarizes the genetic findings to date for blood pressure, and it proposes focused, pathway-based approaches involving epistasis, gene-environment interactions, and next-generation sequencing to further the genetic dissection of blood pressure and hypertension.

2010 translational bioinformatics year in review.

A review of 2010 research in translational bioinformatics provides much to marvel at. We have seen notable advances in personal genomics, pharmacogenetics, and sequencing. At the same time, the infrastructure for the field has burgeoned. While acknowledging that, according to researchers, the members of this field tend to be overly optimistic, the authors predict a bright future.

Non-invasive aneuploidy detection using free fetal DNA and RNA in maternal plasma: recent progress and future possibilities.

BACKGROUND: Cell-free fetal DNA (cff DNA) and RNA can be detected in maternal plasma and used for non-invasive prenatal diagnostics. Recent technical advances have led to a drastic change in the clinical applicability and potential uses of free fetal DNA and RNA. This review summarizes the latest clinical developments in non-invasive prenatal diagnosis in the context of the latest technical developments. METHODS: We searched PubMed with the search terms 'prenatal', 'non-invasive', 'fetal DNA', 'mRNA' and cross-referenced them with 'diagnostics', 'microRNA', 'aneuploidy', 'trisomy' and 'placenta'. We also searched the reference list of the articles identified by this search strategy. RESULTS: Genome-wide methods have been, or can be, successfully applied on total DNA (DNA-seq), methylated DNA immunoprecipitation (with tiling array), microRNA (Megaplex) and total RNA (RNA-seq). Chromosome- or gene-specific assays have been successively applied on placenta RNA (allele ratio) or DNA multiplex ligation-dependent probe amplification (MLPA). These methods are reviewed for their merits and pitfalls with consideration of the placental biology. For the purpose of clarity, the technical and clinical characteristics are limited to non-invasive prenatal detection of chromosomal aneuploidies, with emphasis on trisomy 21. CONCLUSIONS: The technical advances for non-invasive aneuploidy tests based on cff DNA and placental mRNA in maternal plasma have been enormous. Multimarker assays including genome-wide approaches with the option of qualitative information on variation (polymorphism or mutation) besides quantitative information are the preferred methods of choice. The time for population-based, double blind, large-scale clinical cohort trials has come.