Monday 29 June, 2020
James R Lupski, MD, PhD, DSc (hon) Baylor College of Medicine, Houston, TX, USA
Title: Research and clinical Exome Sequencing (cES) in the study of neurodevelopmental and neurodegenerative disease.
10.05 - 10.35 (EDT)
The clinical application of genomics requires the ability to detect genome-wide rare variation of all types. Variant types include single nucleotide variants (SNV), insertion/deletions (indels) and structural variants including copy number variants (CNV). In the research sphere, family based genomics for rare variant detection has helped elucidate “disease genes” and allow molecular entry point into disease mechanism and understanding. Work on Charcot-Marie-Tooth disease and related peripheral neuropathies has helped stimulate studies in human genetics & genomics and allowed novel insights in the fields of mutagenesis and genome instability. This talk will focus on the genomics of neurological
|disease and much of what remains to be done for us as a field to functionally annotate the computationally described ~20,000 genes in the human genome. The more we can characterize the human genome, the rare variation contributing to disease, and the penetrance of pathogenic variants, the more useful our clinical genomics test will be to the practitioner and to moving forward the precision medicine initiative.
Biography: Jim Lupski is Cullen Professor of Molecular and Human Genetics and Professor of Pediatrics. He received his initial scientific training at Cold Spring Harbor Laboratory as an Undergraduate Research Participant (URP) and at New York University receiving his undergraduate degree in chemistry and biology (1979), completing the MD/PhD program in 1985. In 1986, moved to Houston, Texas for clinical training in pediatrics (1986-1989) and medical genetics (1989-1992), then establishing his laboratory at Baylor College of Medicine. Jim is an elected member of AAAS (1996), ASCI (1998), IOM/NAM (2002), and American Academy of Arts and Sciences (2013). For his work in human genomics and elucidation of genomic disorders, he received a DSc honoris causa in 2011 from the Watson School of Biological Sciences at CSHL. He has co-authored > 807 scientific publications, co-edited 3 books including the definitive text on genomic disorders, is a co-inventor on more than a dozen patents and delivered over 536 invited lectures in 38 countries.
Pascale Bomont, PhD INM-INSERM University of Montpellier, Montpellier, France
Title: Exploration of Giant Axonal Neuropathy Unveils Common Pathological Mechanisms amongst CMT Diseases: The Obvious and the Unexpected.
10.35 - 11.05 (EDT)
Giant Axonal Neuropathy (GAN) was first described by Berg and Asbury in 1972, in a child presenting with a progressive motor and sensory neuropathy, and “giant” axons filled with abnormally packed neurofilaments in nerve biopsy. Since then, we learned that Intermediate Filament (IF) aggregation extends beyond neuronal tissues, and that GAN can subsequently spread to the central nervous system. We identified the Gigaxonin-E3 ligase as the defective protein in patients and dedicated our efforts to the elucidation of the key roles of the GAN gene in sustaining neuronal and cytoskeleton integrity. Our laboratory designed novel tools to offer a differential diagnosis between GAN and CMT forms which share common clinical and histopathological features. Moreover, we developed several biological models, from patient’s derived fibroblasts to mouse and zebrafish to decipher the pathological mechanisms in GAN. Altogether, we demonstrate that the Gigaxonin-E3 ligase is a pivotal player of tissue homeostasis, controlling essential cellular pathways of IF architecture and autophagy production.
Considering the evidences of a clinical, histopathological and functional overlap between GAN and several CMT forms, we propose GAN as a CMT disease and as an important model to help understanding the complexity of CMT biology. In particular, we will focus of our recent findings on the role of Gigaxonin-E3 ligase in neuron specification through the regulation of the Sonic Hedgehog pathway, which highlight a developmental origin in GAN, and offer novel functional and therapeutic perspectives for neurodegenerative diseases.
Biography: Pascale Bomont received her PhD in Human Genetics in 2002 (IGBMC, Strasbourg, France). Performing linkage and bioinformatics analysis on the Human Genome, she identified the genetic locus and mutated genes for several neuropathies. Focusing on Gigaxonin, a novel E3-ubiquitin ligase adaptor she found mutated in the CMT-like Giant Axonal Neuropathy (GAN), she conducted a postdoctoral training in Cell Biology (LICR, San Diego, USA) to investigate the cytoskeleton alterations in the pathology. Moving back to France, she was recruited at INSERM in 2007, and was awarded by the ATIP-Avenir prize in 2011 to run a multidisciplinary research program on GAN, at Montpellier University. She developed tools and biological systems in patients, mouse and zebrafish to generate a differential diagnosis test between GAN and CMTs, and to unravel the key roles of the Gigaxonin-E3 ligase in controlling cytoskeleton architecture, autophagy machinery and neuromuscular integrity. She will discuss the recent discovery of a developmental signature in GAN, which is mediated by the control of the Sonic Hedgehog signaling by Gigaxonin and underlies motor deficits in the gan zebrafish.
Merrill Benson, MD Indiana University, Indianapolis, Indiana, USA
Title: FAP - What's New?
11.05 - 11.35 (EDT)
|A lot has happened in the last 20 years for diagnosis and treatment of transthyretin amyloidosis. It is a good time to see where we have been, where were are, and where we should be going.
Biography: MD 1965, First FAP patient 1971, Still learning about all forms of Amyloidosis.
Robert Baloh, MD, PhD Cedars-Sinai Medical Center, Los Angeles, CA, USA
Title: Mitofusins in Axonal Degeneration and Neuroprotection
11.35 - 12.05 (EDT)
Mutations in Mitofusin 2 (MFN2) cause Charcot-Marie-Tooth disease type 2A, typically with dominant inheritance. The peripheral neuropathy in CMT2A is typically early onset, and can be accompanied by a variety of neurologic features including vision loss, spastic paraparesis, and even developmental delay from altered neurodevelopment. Loss of mitochondrial dynamics (fusion, fission, movement and degradation) plays a role in the relative vulnerability of long peripheral axons, and the relative ration of MFN1 to MFN2 in different tissues likely also plays a role in the vulnerability of the nervous system relative to other tissues. Recent work has also suggested that while the balance of fission and fusion of mitochondria is important, that increasing the levels of MFN protein or function using peptides or small molecules may be more broadly neuroprotective.