Publications by authors named "Jm Friedman"

Genome-wide sequencing of the DNA that can be obtained from a newborn screening blood spot could provide predictions of thousands of genetic diseases that are not currently included in universal newborn screening. Most of the serious ethical, legal, privacy, and social concerns raised by genome sequencing of all infants can be avoided by implementing genomic newborn screening in accordance with widely-accepted public health criteria.

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Article Synopsis
  • Spastic tetraplegia and axial hypotonia (STAHP) is a rare neurological disorder in children linked to biallelic SOD1 deficiency, marked by progressive symptoms starting before age 2.
  • Five studies have reported nine cases, primarily related to a common genetic variant in SOD1 that disrupts enzyme function, with one case involving a novel SOD1 variant in a 19-year-old male.
  • The patient exhibited significant neurological decline and MRI findings of cerebellar atrophy, plus new symptoms including immune dysregulation and physical anomalies not previously associated with STAHP.
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Leptin is an adipose tissue hormone that maintains homeostatic control of adipose tissue mass by regulating the activity of specific neural populations controlling appetite and metabolism. Leptin regulates food intake by inhibiting orexigenic agouti-related protein (AGRP) neurons and activating anorexigenic pro-opiomelanocortin (POMC) neurons. However, whereas AGRP neurons regulate food intake on a rapid time scale, acute activation of POMC neurons has only a minimal effect.

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Here, we report a magnetogenetic system, based on a single anti-ferritin nanobody-TRPV1 receptor fusion protein, which regulated neuronal activity when exposed to magnetic fields. Adeno-associated virus (AAV)-mediated delivery of a floxed nanobody-TRPV1 into the striatum of adenosine-2a receptor-Cre drivers resulted in motor freezing when placed in a magnetic resonance imaging machine or adjacent to a transcranial magnetic stimulation device. Functional imaging and fiber photometry confirmed activation in response to magnetic fields.

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The 2024 Lasker~DeBakey Clinical Medical Research Award has been given to Joel Habener and Svetlana Mojsov for their discovery of a new hormone GLP-1(7-37) and to Lotte Knudsen for her role in developing sustained acting versions of this hormone as a treatment for obesity. Each of the three had a distinct set of skills that made this advance possible; Habener is an endocrinologist and molecular biologist, Mojsov is a peptide chemist, and Knudsen is a pharmaceutical scientist. Their collective efforts have done what few thought possible-the development of highly effective medicines for reducing weight.

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Article Synopsis
  • Genetic testing demand is rising, leading to long waitlists and pressure on traditional genetic healthcare, highlighting the need for alternative solutions like e-health tools.* -
  • This study evaluates the Genetics Navigator, a digital platform designed to enhance genetic testing support by integrating with usual care provided by clinicians in both adult and pediatric contexts.* -
  • The effectiveness will be assessed through a randomized controlled trial measuring various outcomes, including participant distress, knowledge, and satisfaction, while considering cost-effectiveness compared to standard care.*
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Importance: Etiologic diagnoses for rare diseases can involve a diagnostic odyssey, with repeated health care interactions and inconclusive diagnostics. Prior studies reported cost savings associated with genome-wide sequencing (GWS) compared with cytogenetic or molecular testing through rapid genetic diagnosis, but there is limited evidence on whether diagnosis from GWS is associated with reduced health care costs.

Objective: To measure changes in health care costs after diagnosis from GWS for Canadian and English children with suspected rare diseases.

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With the increasing availability of long-read sequencing data, high-quality human genome assemblies, and software for fully characterizing tandem repeats, genome-wide genotyping of tandem repeat loci on a population scale becomes more feasible. Such efforts not only expand our knowledge of the tandem repeat landscape in the human genome but also enhance our ability to differentiate pathogenic tandem repeat mutations from benign polymorphisms. To this end, we analyzed 272 genomes assembled using datasets from three public initiatives that employed different long-read sequencing technologies.

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Purpose: We evaluated DECIDE, an online pretest decision-support tool for diagnostic genomic testing, in nongenetics specialty clinics where there are no genetic counselors (GCs).

Methods: Families of children offered genomic testing were eligible to participate. Fifty-six parents/guardians completed DECIDE at home, at their convenience.

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Drugs of abuse are thought to promote addiction in part by "hijacking" brain reward systems, but the underlying mechanisms remain undefined. Using whole-brain FOS mapping and in vivo single-neuron calcium imaging, we found that drugs of abuse augment dopaminoceptive ensemble activity in the nucleus accumbens (NAc) and disorganize overlapping ensemble responses to natural rewards in a cell type-specific manner. Combining FOS-Seq, CRISPR-perturbation, and single-nucleus RNA sequencing, we identified as a molecular substrate that regulates cell type-specific signal transduction in NAc while enabling drugs to suppress natural reward consumption.

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Short tandem repeats (STRs) are a class of repetitive elements, composed of tandem arrays of 1-6 base pair sequence motifs, that comprise a substantial fraction of the human genome. STR expansions can cause a wide range of neurological and neuromuscular conditions, known as repeat expansion disorders, whose age of onset, severity, penetrance and/or clinical phenotype are influenced by the length of the repeats and their sequence composition. The presence of non-canonical motifs, depending on the type, frequency and position within the repeat tract, can alter clinical outcomes by modifying somatic and intergenerational repeat stability, gene expression and mutant transcript-mediated and/or protein-mediated toxicities.

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Purpose: To determine real-world diagnostic rates, cost trajectories, and cost-effectiveness of exome sequencing (ES) and genome sequencing (GS) for children with developmental and/or seizure disorders in British Columbia, Canada.

Methods: Based on medical records review, we estimated real-world costs and outcomes for 491 patients who underwent standard of care (SOC) diagnostic testing at British Columbia Children's Hospital. Results informed a state-transition Markov model examining cost-effectiveness of 3 competing diagnostic strategies: (1) SOC with last-tier access to ES, (2) streamlined ES access, and (3) first-tier GS.

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This white paper was prepared by the Global Alliance for Genomics and Health Regulatory and Ethics Work Stream's Pediatric Task Team to review and provide perspective with respect to ethical, legal, and social issues regarding the return of secondary pharmacogenomic variants in children who have a serious disease or developmental disorder and are undergoing exome or genome sequencing to identify a genetic cause of their condition. We discuss actively searching for and reporting pharmacogenetic/genomic variants in pediatric patients, different methods of returning secondary pharmacogenomic findings to the patient/parents and/or treating clinicians, maintaining these data in the patient's health record over time, decision supports to assist using pharmacogenetic results in future treatment decisions, and sharing information in public databases to improve the clinical interpretation of pharmacogenetic variants identified in other children. We conclude by presenting a series of points to consider for clinicians and policymakers regarding whether, and under what circumstances, routine screening and return of pharmacogenomic variants unrelated to the indications for testing is appropriate in children who are undergoing genome-wide sequencing to assist in the diagnosis of a suspected genetic disease.

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Remedies for the treatment of obesity date to Hippocrates, when patients with obesity were directed to "reduce food and avoid drinking to fullness" and begin "running during the night." Similar recommendations have been repeated ever since, despite the fact that they are largely ineffective. Recently, highly effective therapeutics were developed that may soon enable physicians to manage body weight in patients with obesity in a manner similar to the way that blood pressure is controlled in patients with hypertension.

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Addiction prioritizes drug use over innate needs by "hijacking" brain circuits that direct motivation, but how this develops remains unclear. Using whole-brain FOS mapping and single-neuron calcium imaging, we find that drugs of abuse augment ensemble activity in the nucleus accumbens (NAc) and disorganize overlapping ensemble responses to natural rewards in a cell-type-specific manner. Combining "FOS-Seq", CRISPR-perturbations, and snRNA-seq, we identify as a shared molecular substrate that regulates cell-type-specific signal transductions in NAc while enabling drugs to suppress natural reward responses.

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Over the last decade, utilization of clinical genetics services has grown rapidly, putting increasing pressure on the workforce available to deliver genetic healthcare. To highlight the policy challenges facing Canadian health systems, a needs-based workforce requirements model was developed to determine the number of Canadian patients in 2030 for whom an assessment of hereditary cancer risk would be indicated according to current standards and the numbers of genetic counsellors, clinical geneticists and other physicians with expertise in genetics needed to provide care under a diverse set of scenarios. Our model projects that by 2030, a total of 90 specialist physicians and 326 genetic counsellors (1.

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Here we report a novel suite of magnetogenetic tools, based on a single anti-ferritin nanobody-TRPV1 receptor fusion protein, which regulated neuronal activity when exposed to magnetic fields. AAV-mediated delivery of a floxed nanobody-TRPV1 into the striatum of adenosine 2a receptor-cre driver mice resulted in motor freezing when placed in an MRI or adjacent to a transcranial magnetic stimulation (TMS) device. Functional imaging and fiber photometry both confirmed activation of the target region in response to the magnetic fields.

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Animals that consume fermenting fruit and nectar are at risk of exposure to ethanol and the detrimental effects of inebriation. In this report, we show that the hormone FGF21, which is strongly induced by ethanol in murine and human liver, stimulates arousal from intoxication without changing ethanol catabolism. Mice lacking FGF21 take longer than wild-type littermates to recover their righting reflex and balance following ethanol exposure.

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Running is an increasingly popular sport and form of exercise. Because of the importance of the hip in the biomechanics involved with running, forming the primary connection between the axial and appendicular skeleton of the lower extremities, accurate diagnosis and reporting of hip pathology are vital for appropriate management. This review provides an overview of the most common hip pathologies and injuries encountered in runners.

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Purpose: People with pre-existing conditions may be more susceptible to severe COVID-19 when infected by SARS-CoV-2. The relative risk and severity of SARS-CoV-2 infection in people with rare diseases such as neurofibromatosis type 1 (NF1), neurofibromatosis type 2 (NF2), or schwannomatosis (SWN) is unknown.

Methods: We investigated the proportions of people with NF1, NF2, or SWN in the National COVID Cohort Collaborative (N3C) electronic health record data set who had a positive test result for SARS-CoV-2 or COVID-19.

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Food intake and body weight are tightly regulated by neurons within specific brain regions, including the brainstem, where acute activation of dorsal raphe nucleus (DRN) glutamatergic neurons expressing the glutamate transporter Vglut3 (DRN) drive a robust suppression of food intake and enhance locomotion. Activating Vglut3 neurons in DRN suppresses food intake and increases locomotion, suggesting that modulating the activity of these neurons might alter body weight. Here, we show that DRN neurons project to the lateral hypothalamus (LHA), a canonical feeding center that also reduces food intake.

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