Effect of human H3N2 influenza virus reassortment on influenza incidence and severity during the 2017-18 influenza season in the USA: a retrospective observational genomic analysis.

BACKGROUND: During the 2017-18 influenza season in the USA, there was a high incidence of influenza illness and mortality. However, no apparent antigenic change was identified in the dominant H3N2 viruses, and the severity of the season could not be solely attributed to a vaccine mismatch. We aimed to investigate whether the altered virus properties resulting from gene reassortment were underlying causes of the increased case number and disease severity associated with the 2017-18 influenza season. METHODS: Samples included were collected from patients with influenza who were prospectively recruited during the 2016-17 and 2017-18 influenza seasons at the Johns Hopkins Hospital Emergency Departments in Baltimore, MD, USA, as well as from archived samples from Johns Hopkins Health System sites. Among 647 recruited patients with influenza A virus infection, 411 patients with whole-genome sequences were available in the Johns Hopkins Center of Excellence for Influenza Research and Surveillance network during the 2016-17 and 2017-18 seasons. Phylogenetic trees were constructed based on viral whole-genome sequences. Representative viral isolates of the two seasons were characterised in immortalised cell lines and human nasal epithelial cell cultures, and patients' demographic data and clinical outcomes were analysed. FINDINGS: Unique H3N2 reassortment events were observed, resulting in two predominant strains in the 2017-18 season: HA clade 3C.2a2 and clade 3C.3a, which had novel gene segment constellations containing gene segments from HA clade 3C.2a1 viruses. The reassortant re3C.2a2 viruses replicated with faster kinetics and to a higher peak titre compared with the parental 3C.2a2 and 3C.2a1 viruses (48 h vs 72 h). Furthermore, patients infected with reassortant 3C.2a2 viruses had higher Influenza Severity Scores than patients infected with the parental 3C.2a2 viruses (median 3·00 [IQR 1·00-4·00] vs 1·50 [1·00-2·00]; p=0·018). INTERPRETATION: Our findings suggest that the increased severity of the 2017-18 influenza season was due in part to two intrasubtypes, cocirculating H3N2 reassortant viruses with fitness advantages over the parental viruses. This information could help inform future vaccine development and public health policies. FUNDING: The Center of Excellence for Influenza Research and Response in the US, National Science and Technology Council, and Chang Gung Memorial Hospital in Taiwan.

Identification of Rare Genetic Variants in Familial Spontaneous Coronary Artery Dissection and Evidence for Shared Biological Pathways.

Rare familial spontaneous coronary artery dissection (SCAD) kindreds implicate genetic disease predisposition and provide a unique opportunity for candidate gene discovery. Whole-genome sequencing was performed in fifteen probands with non-syndromic SCAD who had a relative with SCAD, eight of whom had a second relative with extra-coronary arteriopathy. Co-segregating variants and associated genes were prioritized by quantitative variant, gene, and disease-level metrics. Curated public databases were queried for functional relationships among encoded proteins. Fifty-four heterozygous coding variants in thirteen families co-segregated with disease and fulfilled primary filters of rarity, gene variation constraint, and predicted-deleterious protein effect. Secondary filters yielded 11 prioritized candidate genes in 12 families, with high arterial tissue expression (n = 7), high-confidence protein-level interactions with genes associated with SCAD previously (n = 10), and/or previous associations with connective tissue disorders and aortopathies (n = 3) or other vascular phenotypes in mice or humans (n = 11). High-confidence associations were identified among 10 familial SCAD candidate-gene-encoded proteins. A collagen-encoding gene was identified in five families, two with distinct variants in COL4A2. Familial SCAD is genetically heterogeneous, yet perturbations of extracellular matrix, cytoskeletal, and cell-cell adhesion proteins implicate common disease-susceptibility pathways. Incomplete penetrance and variable expression suggest genetic or environmental modifiers.

MutaGAN: A sequence-to-sequence GAN framework to predict mutations of evolving protein populations.

The ability to predict the evolution of a pathogen would significantly improve the ability to control, prevent, and treat disease. Machine learning, however, is yet to be used to predict the evolutionary progeny of a virus. To address this gap, we developed a novel machine learning framework, named MutaGAN, using generative adversarial networks with sequence-to-sequence, recurrent neural networks generator to accurately predict genetic mutations and evolution of future biological populations. MutaGAN was trained using a generalized time-reversible phylogenetic model of protein evolution with maximum likelihood tree estimation. MutaGAN was applied to influenza virus sequences because influenza evolves quickly and there is a large amount of publicly available data from the National Center for Biotechnology Information's Influenza Virus Resource. MutaGAN generated 'child' sequences from a given 'parent' protein sequence with a median Levenshtein distance of 4.00 amino acids. Additionally, the generator was able to generate sequences that contained at least one known mutation identified within the global influenza virus population for 72.8 per cent of parent sequences. These results demonstrate the power of the MutaGAN framework to aid in pathogen forecasting with implications for broad utility in evolutionary prediction for any protein population.

The Development of an Infrastructure to Facilitate the Use of Whole Genome Sequencing for Population Health.

The clinical use of genomic analysis has expanded rapidly resulting in an increased availability and utility of genomic information in clinical care. We have developed an infrastructure utilizing informatics tools and clinical processes to facilitate the use of whole genome sequencing data for population health management across the healthcare system. Our resulting framework scaled well to multiple clinical domains in both pediatric and adult care, although there were domain specific challenges that arose. Our infrastructure was complementary to existing clinical processes and well-received by care providers and patients. Informatics solutions were critical to the successful deployment and scaling of this program. Implementation of genomics at the scale of population health utilizes complicated technologies and processes that for many health systems are not supported by current information systems or in existing clinical workflows. To scale such a system requires a substantial clinical framework backed by informatics tools to facilitate the flow and management of data. Our work represents an early model that has been successful in scaling to 29 different genes with associated genetic conditions in four clinical domains. Work is ongoing to optimize informatics tools; and to identify best practices for translation to smaller healthcare systems.

Lassa Virus Infection: a Summary for Clinicians.

OBJECTIVES: This summary on Lassa virus (LASV) infection and Lassa fever disease (LF) was developed from a clinical perspective to provide clinicians with a condensed, accessible understanding of the current literature. The information provided highlights pathogenesis, clinical features, and diagnostics emphasizing therapies and vaccines that have demonstrated potential value for use in clinical or research environments. METHODS: We conducted an integrative literature review on the clinical and pathological features, vaccines, and treatments for LASV infection, focusing on recent studies and in vivo evidence from humans and/or non-human primates (NHPs), when available. RESULTS: Two antiviral medications with potential benefit for the treatment of LASV infection and 1 for post-exposure prophylaxis were identified, although a larger number of therapeutic candidates are currently being evaluated. Multiple vaccine platforms are in pre-clinical development for LASV prevention, but data from human clinical trials are not yet available. CONCLUSION: We provide succinct summaries of medical countermeasures against LASV to give the busy clinician a rapid reference. Although there are no approved drugs or vaccines for LF, we provide condensed information from a literature review for measures that can be taken when faced with a suspected infection, including investigational treatment options and hospital engineering controls.

Performance Alteration Induced by Weight Cutting in Mixed Martial Arts-A Biomechanical Pilot Investigation.

Currently, there are pros and cons of research results related to weight cutting in combat sports, resulting in inconclusive results regarding the effects of weight-cut on athletes' performance, and biomechanical investigations are hardly seen. Therefore, this pilot study tried to fill the gap by initiating an exploration in real-life competitions. It is our hope to add biomechanical insights (advantages/disadvantages) that would discern the impact of weight cutting on competitive performance and help to structure hypotheses in future research. The method consisted of 3D motion capture, EMG measurement and biomechanical modeling. Through the synchronized data, striking power, striking accuracy and reaction time were quantitatively determined. Pre- and post-test design was used to test common strikes before weight cutting and 24 h after weigh-in. Seven male athletes from local clubs were tested during regional competitions. Results were characterized by using descriptive statistics (means and standard deviations) and T-tests were performed to contrast differences between the pre- and post-tests. This pilot study has revealed that there is actually weight-regain instead of weight-loss. The weight-regain would speed up the perceptional and total reaction, slow down the limbs' movement, worsen the striking accuracy and, possibly, decrease the strike power. The preliminary results are inconclusive regarding the competitive advantages/disadvantages induced by weight cutting. Further biomechanical studies are needed to deal with the controversial subject more objectively and scientifically.

Pediatric brain tumor cell lines exhibit miRNA-depleted, Y RNA-enriched extracellular vesicles.

BACKGROUND: Medulloblastoma (MB) and diffuse infiltrative pontine glioma (DIPG) are malignant pediatric tumors. Extracellular vesicles (EVs) and their bioactive cargoes have been implicated in tumorigenesis. Most studies have focused on adult tumors, therefore the role of EVs and the noncoding RNA (ncRNA) landscape in pediatric brain tumors is not fully characterized. The overall aim of this pilot study was to isolate EVs from MB and DIPG patient-derived cell lines and to explore the small ncRNA transcriptome. METHODS: EVs from 3 DIPG and 4 MB patient-derived cell lines were analyzed. High-throughput next generation sequencing interrogated the short non-coding RNA (ncRNA) transcriptome. Known and novel miRNAs were quantified. Differential expression analysis, in silico target prediction, and functional gene enrichment were performed. RESULTS: EV secretomes from MB and DIPG patient-derived cell lines demonstrated discrete ncRNA biotypes. Notably, miRNAs were depleted and Y RNAs were enriched in EV samples. Hierarchical cluster analysis revealed high discrimination in miRNA expression between DIPG and MB cell lines and RNA-Seq identified novel miRNAs not previously implicated in MB or DIPG pathogenesis. Known and putative target genes of dysregulated miRNAs were identified. Functional annotation analysis of the target genes for differentially expressed EV-and parental-derived miRNAs revealed significant cancer-related pathway involvement. CONCLUSIONS: This hypothesis-generating study demonstrated that pediatric brain tumor-derived cell lines secrete EVs comprised of various ncRNA cargoes. Validation of these findings in patient samples may provide new insights into the pediatric brain tumor microenvironment and identification of novel therapeutic candidates.

Nosocomial Respiratory Infections in a Rural Zambian Hospital.

The burden of nosocomial respiratory infections in rural southern Africa is poorly understood. We established a surveillance program at a rural Zambian hospital to detect influenza-like illness (ILI) and respiratory infections among hospitalized patients and a cohort of healthcare workers (HCWs). Nasopharyngeal specimens from symptomatic patients and HCWs underwent broadly multiplexed molecular testing to detect viruses and atypical bacteria. During 1 year of surveillance, 15 patients (1.7% of admissions) developed ILI more than 48 hours after admission. Among 44 HCWs, 19 (43%) experienced at least one ILI episode, with a total of 31 ILI episodes detected. Respiratory viruses were detected in 45% of patient and 55% of HCW specimens. The cumulative incidence of influenza infection among HCWs over 1 year was 9%. Overall, respiratory viruses were commonly found among patients and HCWs in a rural Zambian hospital with limited infection control infrastructure.

Identification of H3N2 NA and PB1-F2 genetic variants and their association with disease symptoms during the 2014-15 influenza season.

The 2014-15 influenza season saw the emergence of an H3N2 antigenic drift variant that formed the 3C.2a HA clade. Whole viral genomes were sequenced from nasopharyngeal swabs of ninety-four patients with confirmed influenza A virus infection and primary human nasal epithelial cell cultures used to efficiently isolate H3N2 viruses. The isolates were classified by HA clade and the presence of a new set of co-selected mutations in NA (a glycosylation site, NAg+) and PB1-F2 (H75P). The NA and PB1-F2 mutations were present in a subset of clade 3C.2a viruses (NAg+F2P), which dominated during the subsequent influenza seasons. In human nasal epithelial cell cultures, a virus with the novel NAg+F2P genotype replicated less well compared with a virus with the parental genotype. Retrospective analyses of clinical data showed that NAg+F2P genotype viruses were associated with increased cough and shortness of breath in infected patients.

Differential disease severity and whole-genome sequence analysis for human influenza A/H1N1pdm virus in 2015-2016 influenza season.

During the 2015-16 winter, the US experienced a relatively mild influenza season compared to Taiwan, which had a higher number of total and severe cases. While H1N1pdm viruses dominated global surveillance efforts that season, the global distribution of genetic variants and their contributions to disease severity have not been investigated. Samples collected from influenza A-positive patients by the Johns Hopkins Center of Excellence for Influenza Research and Surveillance active surveillance in the emergency rooms in Baltimore, Maryland, USA, and northern Taiwan between November 2015 and April 2016, were processed for influenza A virus whole-genome sequencing. In Baltimore, the majority of the viruses were the H1N1pdm clade 6B.1 and no H1N1pdm clade 6B.2 viruses were detected. In northern Taiwan, more than half of the H1N1pdm viruses were clade 6B.1 and 38% were clade 6B.2, consistent with the global observation that most 6B.2 viruses circulated in Asia and not North America. Whole virus genome sequence analysis identified two genetic subgroups present in each of the 6B.1 and 6B.2 clades and one 6B.1 interclade reassortant virus. Clinical data showed 6B.2 patients had more disease symptoms including higher crude and inverse probability weighted odds of pneumonia than 6B.1 patients, suggesting 6B.2 circulation may be one of the reasons for the severe flu season in Taiwan. Local surveillance efforts linking H1N1pdm virus sequences to patient clinical and demographic data improve our understanding of influenza circulation and disease potential.

Genomic diversity of SARS-CoV-2 during early introduction into the Baltimore-Washington metropolitan area.

The early COVID-19 pandemic was characterized by rapid global spread. In Maryland and Washington, DC, United States, more than 2500 cases were reported within 3 weeks of the first COVID-19 detection in March 2020. We aimed to use genomic sequencing to understand the initial spread of SARS-CoV-2 - the virus that causes COVID-19 - in the region. We analyzed 620 samples collected from the Johns Hopkins Health System during March 11-31, 2020, comprising 28.6% of the total cases in Maryland and Washington, DC. From these samples, we generated 114 complete viral genomes. Analysis of these genomes alongside a subsampling of over 1000 previously published sequences showed that the diversity in this region rivaled global SARS-CoV-2 genetic diversity at that time and that the sequences belong to all of the major globally circulating lineages, suggesting multiple introductions into the region. We also analyzed these regional SARS-CoV-2 genomes alongside detailed clinical metadata and found that clinically severe cases had viral genomes belonging to all major viral lineages. We conclude that efforts to control local spread of the virus were likely confounded by the number of introductions into the region early in the epidemic and the interconnectedness of the region as a whole.

Genetic Association Between Hypoplastic Left Heart Syndrome and Cardiomyopathies.

BACKGROUND: Hypoplastic left heart syndrome (HLHS) with risk of poor outcome has been linked to MYH6 variants, implicating overlap in genetic etiologies of structural and myopathic heart disease. METHODS: Whole genome sequencing was performed in 197 probands with HLHS, 43 family members, and 813 controls. Data were filtered for rare, segregating variants in 3 index families comprised of an HLHS proband and relative(s) with cardiomyopathy. Whole genome sequencing data from cases and controls were compared for rare variant burden across 56 cardiomyopathy genes utilizing a weighted burden test approach, accounting for multiple testing using a Bonferroni correction. RESULTS: A pathogenic MYBPC3 nonsense variant was identified in the first proband who underwent cardiac transplantation for diastolic heart failure, her father with left ventricular noncompaction, and 2 fourth-degree relatives with hypertrophic cardiomyopathy. A likely pathogenic RYR2 missense variant was identified in the second proband, a second-degree relative with aortic dilation, and a fourth-degree relative with dilated cardiomyopathy. A pathogenic RYR2 exon 3 in-frame deletion was identified in the third proband diagnosed with catecholaminergic polymorphic ventricular tachycardia and his father with left ventricular noncompaction and catecholaminergic polymorphic ventricular tachycardia. To further investigate HLHS-cardiomyopathy gene associations in cases versus controls, rare variant burden testing of 56 genes revealed enrichment in MYH6 (P=0.000068). Rare, predicted-damaging MYH6 variants were identified in 10% of probands in our cohort-4 with familial congenital heart disease, 4 with compound heterozygosity (3 with systolic ventricular dysfunction), and 4 with MYH6-FLNC synergistic heterozygosity. CONCLUSIONS: Whole genome sequencing in multiplex families, proband-parent trios, and case-control cohorts revealed defects in cardiomyopathy-associated genes in patients with HLHS, which may portend impaired functional reserve of the single-ventricle circulation.

Patient-specific genomics and cross-species functional analysis implicate LRP2 in hypoplastic left heart syndrome.

Congenital heart diseases (CHDs), including hypoplastic left heart syndrome (HLHS), are genetically complex and poorly understood. Here, a multidisciplinary platform was established to functionally evaluate novel CHD gene candidates, based on whole-genome and iPSC RNA sequencing of a HLHS family-trio. Filtering for rare variants and altered expression in proband iPSCs prioritized 10 candidates. siRNA/RNAi-mediated knockdown in healthy human iPSC-derived cardiomyocytes (hiPSC-CM) and in developing Drosophila and zebrafish hearts revealed that LDL receptor-related protein LRP2 is required for cardiomyocyte proliferation and differentiation. Consistent with hypoplastic heart defects, compared to patents the proband's iPSC-CMs exhibited reduced proliferation. Interestingly, rare, predicted-damaging LRP2 variants were enriched in a HLHS cohort; however, understanding their contribution to HLHS requires further investigation. Collectively, we have established a multi-species high-throughput platform to rapidly evaluate candidate genes and their interactions during heart development, which are crucial first steps toward deciphering oligogenic underpinnings of CHDs, including hypoplastic left hearts.

Genomic Diversity of SARS-CoV-2 During Early Introduction into the United States National Capital Region.

BACKGROUND: The early COVID-19 pandemic has been characterized by rapid global spread. In the United States National Capital Region, over 2,000 cases were reported within three weeks of its first detection in March 2020. We aimed to use genomic sequencing to understand the initial spread of SARS-CoV-2, the virus that causes COVID-19, in the region. By correlating genetic information to disease phenotype, we also aimed to gain insight into any correlation between viral genotype and case severity or transmissibility. METHODS: We performed whole genome sequencing of clinical SARS-CoV-2 samples collected in March 2020 by the Johns Hopkins Health System. We analyzed these regional SARS-CoV-2 genomes alongside detailed clinical metadata and the global phylogeny to understand early establishment of the virus within the region. RESULTS: We analyzed 620 samples from the Johns Hopkins Health System collected between March 11-31, 2020, comprising 37.3% of the total cases in Maryland during this period. We selected 143 of these samples for sequencing, generating 114 complete viral genomes. These genomes belong to all five major Nextstrain-defined clades, suggesting multiple introductions into the region and underscoring the diversity of the regional epidemic. We also found that clinically severe cases had genomes belonging to all of these clades. CONCLUSIONS: We established a pipeline for SARS-CoV-2 sequencing within the Johns Hopkins Health system, which enabled us to capture the significant viral diversity present in the region as early as March 2020. Efforts to control local spread of the virus were likely confounded by the number of introductions into the region early in the epidemic and interconnectedness of the region as a whole.

Mitochondrial DNA: Hotspot for Potential Gene Modifiers Regulating Hypertrophic Cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) is a prevalent and untreatable cardiovascular disease with a highly complex clinical and genetic causation. HCM patients bearing similar sarcomeric mutations display variable clinical outcomes, implying the involvement of gene modifiers that regulate disease progression. As individuals exhibiting mutations in mitochondrial DNA (mtDNA) present cardiac phenotypes, the mitochondrial genome is a promising candidate to harbor gene modifiers of HCM. Herein, we sequenced the mtDNA of isogenic pluripotent stem cell-cardiomyocyte models of HCM focusing on two sarcomeric mutations. This approach was extended to unrelated patient families totaling 52 cell lines. By correlating cellular and clinical phenotypes with mtDNA sequencing, potentially HCM-protective or -aggravator mtDNA variants were identified. These novel mutations were mostly located in the non-coding control region of the mtDNA and did not overlap with those of other mitochondrial diseases. Analysis of unrelated patients highlighted family-specific mtDNA variants, while others were common in particular population haplogroups. Further validation of mtDNA variants as gene modifiers is warranted but limited by the technically challenging methods of editing the mitochondrial genome. Future molecular characterization of these mtDNA variants in the context of HCM may identify novel treatments and facilitate genetic screening in cardiomyopathy patients towards more efficient treatment options.

Short non-coding RNA sequencing of glioblastoma extracellular vesicles.

INTRODUCTION: Like all nucleated cells, glioblastoma (GBM) cells shed small membrane-encapsulated particles called extracellular vesicles (EVs). EVs can transfer oncogenic components and promote tumor growth by transferring short non-coding RNAs, altering target cell gene expression. Furthermore, GBM-derived EVs can be detected in blood and have potential to serve as liquid biopsies. METHODS: EVs were harvested from culture supernatants from human GBM cell lines, purified via sequential centrifugation, and quantified by nanoparticle tracking. RNA was isolated and short non-coding RNA was sequenced. Data was analyzed via the OASIS-2.0 platform using HG38. MirTarBase and MirDB interrogated validated/predicted miRNA-gene interactions respectively. RESULTS: Many short non-coding RNA's were identified within GBM EV's. In keeping with earlier reports utilizing GBM EV micro-RNA (miRNA) arrays, these included abundant micro-RNA's including miR-21. However, RNA sequencing revealed a total of 712 non-coding RNA sequences most of which have not been associated with GBM EV's previously. These included many RNA species (piRNA, snoRNA, snRNA, rRNA and yRNAs) in addition to miRNA's. miR-21-5p, let-7b-5p, miR-3182, miR-4448, let-7i-5p constituted highest overall expression. Top genes targeted by non-coding RNA's were highly conserved and specific for cell cycle, PI3K/Akt signaling, p53 and Glioma curated KEGG pathways. CONCLUSIONS: Next generation short non-coding RNA sequencing on GBM EV's validates findings from earlier studies using miRNA arrays but also demonstrates expression of many additional non-coding RNA sequences and classes previously unassociated with GBM. This may yield important insights into pathophysiology, point to new therapeutic targets, and help develop new biomarkers for disease burden and treatment response.

Long-lived particles at the energy frontier: the MATHUSLA physics case.

We examine the theoretical motivations for long-lived particle (LLP) signals at the LHC in a comprehensive survey of standard model (SM) extensions. LLPs are a common prediction of a wide range of theories that address unsolved fundamental mysteries such as naturalness, dark matter, baryogenesis and neutrino masses, and represent a natural and generic possibility for physics beyond the SM (BSM). In most cases the LLP lifetime can be treated as a free parameter from the [Formula: see text]m scale up to the Big Bang Nucleosynthesis limit of [Formula: see text] m. Neutral LLPs with lifetimes above [Formula: see text]100 m are particularly difficult to probe, as the sensitivity of the LHC main detectors is limited by challenging backgrounds, triggers, and small acceptances. MATHUSLA is a proposal for a minimally instrumented, large-volume surface detector near ATLAS or CMS. It would search for neutral LLPs produced in HL-LHC collisions by reconstructing displaced vertices (DVs) in a low-background environment, extending the sensitivity of the main detectors by orders of magnitude in the long-lifetime regime. We study the LLP physics opportunities afforded by a MATHUSLA-like detector at the HL-LHC, assuming backgrounds can be rejected as expected. We develop a model-independent approach to describe the sensitivity of MATHUSLA to BSM LLP signals, and compare it to DV and missing energy searches at ATLAS or CMS. We then explore the BSM motivations for LLPs in considerable detail, presenting a large number of new sensitivity studies. While our discussion is especially oriented towards the long-lifetime regime at MATHUSLA, this survey underlines the importance of a varied LLP search program at the LHC in general. By synthesizing these results into a general discussion of the top-down and bottom-up motivations for LLP searches, it is our aim to demonstrate the exceptional strength and breadth of the physics case for the construction of the MATHUSLA detector.

Rare Missense Variants in TLN1 Are Associated With Familial and Sporadic Spontaneous Coronary Artery Dissection.

BACKGROUND: Spontaneous coronary artery dissection (SCAD) is an uncommon idiopathic disorder predominantly affecting young, otherwise healthy women. Rare familial cases reveal a genetic predisposition to disease. The aim of this study was to identify a novel susceptibility gene for SCAD. METHODS: Whole-exome sequencing was performed in a family comprised of 3 affected individuals and filtered to identify rare, predicted deleterious, segregating variants. Immunohistochemical staining was used to evaluate protein expression of the identified candidate gene. The prevalence and spectrum of rare (<0.1%) variants within binding domains was determined by next-generation sequencing or denaturing high-performance liquid chromatography in a sporadic SCAD cohort of 675 unrelated individuals. RESULTS: We identified a rare heterozygous missense variant within a highly conserved ß-integrin-binding domain of TLN1 segregating with familial SCAD. TLN1 encodes talin 1-a large cytoplasmic protein of the integrin adhesion complex that links the actin cytoskeleton and extracellular matrix. Consistent with high mRNA expression in arterial tissues, robust immunohistochemical staining of talin 1 was demonstrated in coronary arteries. Nine additional rare heterozygous missense variants in TLN1 were identified in 10 sporadic cases. Incomplete penetrance, suggesting genetic or environmental modifiers of this episodic disorder, was evident in the familial case and 5 individuals with sporadic SCAD from whom parental DNA was available. CONCLUSIONS: Our findings reveal TLN1 as a disease-associated gene in familial and sporadic SCAD and, together with abnormal vascular phenotypes reported in animal models of talin 1 disruption, implicate impaired structural integrity of the coronary artery cytoskeleton in SCAD susceptibility.

Noncardiac genetic predisposition in sudden infant death syndrome.

PURPOSE: Sudden infant death syndrome (SIDS) is the commonest cause of sudden death of an infant; however, the genetic basis remains poorly understood. We aimed to identify noncardiac genes underpinning SIDS and determine their prevalence compared with ethnically matched controls. METHODS: Using exome sequencing we assessed the yield of ultrarare nonsynonymous variants (minor allele frequency [MAF] ≤0.00005, dominant model; MAF ≤0.01, recessive model) in 278 European SIDS cases (62% male; average age =2.7 ± 2 months) versus 973 European controls across 61 noncardiac SIDS-susceptibility genes. The variants were classified according to American College of Medical Genetics and Genomics criteria. Case-control, gene-collapsing analysis was performed in eight candidate biological pathways previously implicated in SIDS pathogenesis. RESULTS: Overall 43/278 SIDS cases harbored an ultrarare single-nucleotide variant compared with 114/973 controls (15.5 vs. 11.7%, p=0.10). Only 2/61 noncardiac genes were significantly overrepresented in cases compared with controls (ECE1, 3/278 [1%] vs. 1/973 [0.1%] p=0.036; SLC6A4, 2/278 [0.7%] vs. 1/973 [0.1%] p=0.049). There was no difference in yield of pathogenic or likely pathogenic variants between cases and controls (1/278 [0.36%] vs. 4/973 [0.41%]; p=1.0). Gene-collapsing analysis did not identify any specific biological pathways to be significantly associated with SIDS. CONCLUSIONS: A monogenic basis for SIDS amongst the previously implicated noncardiac genes and their encoded biological pathways is negligible.