Huntington's disease phenocopy syndromes revisited: a clinical comparison and next-generation sequencing exploration.

Background: Genetic testing for Huntington's disease (HD) was initially usually positive but more recently the negative rate has increased: patients with negative HD tests are described as having HD phenocopy syndromes (HDPC). This study examines their clinical characteristics and investigates the genetic causes of HDPC.

Methods: Clinical data from neurogenetics clinics and HDPC gene-panel data were analysed.

Therapeutic validation of MMR-associated genetic modifiers in a human ex vivo model of Huntington disease.

The pathological huntingtin (HTT) trinucleotide repeat underlying Huntington disease (HD) continues to expand throughout life. Repeat length correlates both with earlier age at onset (AaO) and faster progression, making slowing its expansion an attractive therapeutic approach. Genome-wide association studies have identified candidate variants associated with altered AaO and progression, with many found in DNA mismatch repair (MMR)-associated genes.

Impact of veteran-led peer mentorship on posttraumatic stress disorder.

Peer mentorship shows promise as a strategy to support veteran mental health. A community-academic partnership involving a veteran-led nonprofit organization and institutions of higher education evaluated a collaboratively developed peer mentor intervention. We assessed posttraumatic stress disorder (PTSD), postdeployment experiences, social functioning, and psychological strengths at baseline, midpoint, and 12-week discharge using the PTSD Checklist for DSM-5 (PCL-5), Deployment Risk and Resilience Inventory-2, Social Adaptation Self-evaluation Scale, and Values in Action Survey.

Genetic modifiers of repeat expansion disorders.

Repeat expansion disorders (REDs) are monogenic diseases caused by a sequence of repetitive DNA expanding above a pathogenic threshold. A common feature of the REDs is a strong genotype-phenotype correlation in which a major determinant of age at onset (AAO) and disease progression is the length of the inherited repeat tract. Over a disease-gene carrier's life, the length of the repeat can expand in somatic cells, through the process of somatic expansion which is hypothesised to drive disease progression.

PolyQ length-dependent metabolic alterations and DNA damage drive human astrocyte dysfunction in Huntington's disease.

Huntington's Disease (HD) is a neurodegenerative disease caused by a polyglutamine (polyQ) expansion in the Huntingtin gene. Astrocyte dysfunction is known to contribute to HD pathology, however our understanding of the molecular pathways involved is limited. Transcriptomic analysis of patient-derived PSC (pluripotent stem cells) astrocyte lines revealed that astrocytes with similar polyQ lengths shared a large number of differentially expressed genes (DEGs).

Intellectual enrichment and genetic modifiers of cognition and brain volume in Huntington's disease.

An important step towards the development of treatments for cognitive impairment in ageing and neurodegenerative diseases is to identify genetic and environmental modifiers of cognitive function and understand the mechanism by which they exert an effect. In Huntington's disease, the most common autosomal dominant dementia, a small number of studies have identified intellectual enrichment, i.e.

Abnormal molecular signatures of inflammation, energy metabolism, and vesicle biology in human Huntington disease peripheral tissues.

Background: A major challenge in neurodegenerative diseases concerns identifying biological disease signatures that track with disease progression or respond to an intervention. Several clinical trials in Huntington disease (HD), an inherited, progressive neurodegenerative disease, are currently ongoing. Therefore, we examine whether peripheral tissues can serve as a source of readily accessible biological signatures at the RNA and protein level in HD patients.

Potential disease-modifying therapies for Huntington's disease: lessons learned and future opportunities.

Huntington's disease is the most frequent autosomal dominant neurodegenerative disorder; however, no disease-modifying interventions are available for patients with this disease. The molecular pathogenesis of Huntington's disease is complex, with toxicity that arises from full-length expanded huntingtin and N-terminal fragments of huntingtin, which are both prone to misfolding due to proteolysis; aberrant intron-1 splicing of the HTT gene; and somatic expansion of the CAG repeat in the HTT gene. Potential interventions for Huntington's disease include therapies targeting huntingtin DNA and RNA, clearance of huntingtin protein, DNA repair pathways, and other treatment strategies targeting inflammation and cell replacement.

Veteran Engagement in Health Services Research: a Conceptual Model.

With 20 million living veterans and millions more immediate family members, and approximately 9 million veterans enrolled in the nationally networked VA healthcare system, representing the interests and needs of veterans in this complex community is a substantial endeavor. Based on the importance of engaging Veterans in research, the VA Health Services Research and Development (HSR&D) Service convened a Working Group of VA researchers and Veterans to conduct a review of patient engagement models and develop recommendations for an approach to engage Veterans in health research that would incorporate their unique lived experiences and interests, and their perspectives on research priorities. The Working Group considered the specific context for Veteran engagement in research that includes other VA stakeholders from the operational and clinical leadership of the VA Health Administration (VHA).

Engaging veteran stakeholders to identify patient-centred research priorities for optimizing implementation of lung cancer screening.

Background: Patient engagement in research agenda setting is increasingly being seen as a strategy to improve the responsiveness of healthcare to patient priorities. Implementation of low-dose computed tomography (LDCT) screening for lung cancer is suboptimal, suggesting that research is needed.

Objectives: This study aimed to describe an approach by which a Veteran patient group worked with other stakeholders to develop a research agenda for LDCT screening and to describe the research questions that they prioritized.

Dystrophin deficiency affects human astrocyte properties and response to damage.

In addition to progressive muscular degeneration due to dystrophin mutations, 1/3 of Duchenne muscular dystrophy (DMD) patients present cognitive deficits. However, there is currently an incomplete understanding about the function of the multiple dystrophin isoforms in human brains. Here, we tested the hypothesis that dystrophin deficiency affects glial function in DMD and could therefore contribute to neural impairment.

FAN1 controls mismatch repair complex assembly via MLH1 retention to stabilize CAG repeat expansion in Huntington's disease.

CAG repeat expansion in the HTT gene drives Huntington's disease (HD) pathogenesis and is modulated by DNA damage repair pathways. In this context, the interaction between FAN1, a DNA-structure-specific nuclease, and MLH1, member of the DNA mismatch repair pathway (MMR), is not defined. Here, we identify a highly conserved SPYF motif at the N terminus of FAN1 that binds to MLH1.

Subcellular Localization And Formation Of Huntingtin Aggregates Correlates With Symptom Onset And Progression In A Huntington'S Disease Model.

Huntington's disease is caused by the expansion of a CAG repeat within exon 1 of the gene, which is unstable, leading to further expansion, the extent of which is brain region and peripheral tissue specific. The identification of DNA repair genes as genetic modifiers of Huntington's disease, that were known to abrogate somatic instability in Huntington's disease mouse models, demonstrated that somatic CAG expansion is central to disease pathogenesis, and that the CAG repeat threshold for pathogenesis in specific brain cells might not be known. We have previously shown that the gene is incompletely spliced generating a small transcript that encodes the highly pathogenic exon 1 HTT protein.

Huntington disease: new insights into molecular pathogenesis and therapeutic opportunities.

Huntington disease (HD) is a neurodegenerative disease caused by CAG repeat expansion in the huntingtin gene (HTT) and involves a complex web of pathogenic mechanisms. Mutant HTT (mHTT) disrupts transcription, interferes with immune and mitochondrial function, and is aberrantly modified post-translationally. Evidence suggests that the mHTT RNA is toxic, and at the DNA level, somatic CAG repeat expansion in vulnerable cells influences the disease course.

Therapeutic strategies for Huntington's disease.

Purpose Of Review: Huntington's disease is a fatal autosomal dominant neurodegenerative disorder caused by a trinucleotide expansion in the HTT gene, and current therapies focus on symptomatic treatment. This review explores therapeutic approaches that directly target the pathogenic mutation, disrupt HTT mRNA or its translation.

Recent Findings: Zinc-finger transcription repressors and CRISPR-Cas9 therapies target HTT DNA, thereby preventing all downstream pathogenic mechanisms.

A genetic association study of glutamine-encoding DNA sequence structures, somatic CAG expansion, and DNA repair gene variants, with Huntington disease clinical outcomes.

Background: Huntington disease (HD) is caused by an unstable CAG/CAA repeat expansion encoding a toxic polyglutamine tract. Here, we tested the hypotheses that HD outcomes are impacted by somatic expansion of, and polymorphisms within, the HTT CAG/CAA glutamine-encoding repeat, and DNA repair genes.

Methods: The sequence of the glutamine-encoding repeat and the proportion of somatic CAG expansions in blood DNA from participants inheriting 40 to 50 CAG repeats within the TRACK-HD and Enroll-HD cohorts were determined using high-throughput ultra-deep-sequencing.

MSH3 modifies somatic instability and disease severity in Huntington's and myotonic dystrophy type 1.

The mismatch repair gene MSH3 has been implicated as a genetic modifier of the CAG·CTG repeat expansion disorders Huntington's disease and myotonic dystrophy type 1. A recent Huntington's disease genome-wide association study found rs557874766, an imputed single nucleotide polymorphism located within a polymorphic 9 bp tandem repeat in MSH3/DHFR, as the variant most significantly associated with progression in Huntington's disease. Using Illumina sequencing in Huntington's disease and myotonic dystrophy type 1 subjects, we show that rs557874766 is an alignment artefact, the minor allele for which corresponds to a three-repeat allele in MSH3 exon 1 that is associated with a reduced rate of somatic CAG·CTG expansion (P = 0.

A case report of successful treatment of high-output heart failure secondary to hereditary haemorrhagic telangiectasia with bevacizumab.

Hereditary haemorrhagic telangiectasia (HHT) is a rare autosomal dominant disorder resulting in uncontrolled multisystem angiogenesis. The pathogenesis of this disease is thought to relate to elevated levels of transforming growth factor beta and vascular endothelial growth factor (VEGF). The frail arteriovenous malformations (AVMs) give rise to complications including haemorrhage and shunting.

FAN1 modifies Huntington's disease progression by stabilizing the expanded HTT CAG repeat.

Huntington's disease (HD) is an inherited neurodegenerative disease caused by an expanded CAG repeat in the huntingtin (HTT) gene. CAG repeat length explains around half of the variation in age at onset (AAO) but genetic variation elsewhere in the genome accounts for a significant proportion of the remainder. Genome-wide association studies have identified a bidirectional signal on chromosome 15, likely underlain by FANCD2- and FANCI-associated nuclease 1 (FAN1), a nuclease involved in DNA interstrand cross link repair.

Stroke thrombolysis complicated by ST elevation myocardial infarction (STEMI).

An 84-year-old male Jehovah's Witness presented to the emergency department 1 hour after onset of left facial droop and left upper limb weakness. Thrombolytic stroke treatment was commenced as per local thrombolytic protocol with intravenous recombinant tissue plasminogen activator (rtPA) at 2 hours and 25 min following onset of symptoms. Almost immediately after rtPA infusion the patient reported chest pain and had ECG changes consistent with a diagnosis of anterior ST elevation myocardial infarction.

Respiratory bronchiolitis-associated interstitial lung disease secondary to electronic nicotine delivery system use confirmed with open lung biopsy.

As a modern phenomenon, there is currently limited understanding of the possible toxic effects and broader implications of electronic nicotine delivery systems (ENDS). Large volumes of aerosolized particles are inhaled during "vaping" and there are now an increasing number of case reports demonstrating toxic effects of ENDS, as well as human studies demonstrating impaired lung function in users. This article presents a case of respiratory bronchiolitis interstitial lung disease (RB-ILD) precipitated by vaping in a 33-year-old male with 10 pack years of traditional cigarette and prior treatment for mixed germ cell tumour.