Medical Sciences Commons^™

Deep Phenotyping Of Post-Infectious Myalgic Encephalomyelitis/Chronic Fatigue Syndrome, Brian Walitt, Komudi Singh, Samuel R. Lamunion, Mark Hallett, Steve Jacobson, Kong Chen, Yoshimi Enose-Akahata, Richard Apps, Jennifer J. Barb, Patrick Bedard, Robert J. Brychta, Ashura Williams Buckley, Peter D. Burbelo, Brice Calco, Brianna Cathay, Li Chen, Snigdha Chigurupati, Jinguo Chen, Foo Cheung, Lisa M.K. Chin, Benjamin W. Coleman, Amber B. Courville, Madeleine S. Deming, Bart Drinkard, Li Rebekah Feng, Luigi Ferrucci, Scott A. Gabel, Angelique Gavin, David S. Goldstein, Shahin Hassanzadeh, Sean C. Horan, Silvina G. Horovitz, Kory R. Johnson, Anita Jones Govan, Kristine M. Knutson, Joy D. Kreskow, Mark Levin, Jonathan J. Lyons, Nicholas Madian, Nasir Malik, Andrew L. Mammen, John A. Mcculloch, Patrick M. Mcgurrin, Joshua D. Milner, Ruin Moaddel, Geoffrey A. Mueller, Amrita Mukherjee, Sandra Muñoz-Braceras, Gina Norato, Katherine Pak, Iago Pinal-Fernandez, Traian Popa, Lauren B. Reoma, Michael N. Sack, Farinaz Safavi, Leorey N. Saligan, Brian A. Sellers, Stephen Sinclair, Bryan Smith, Joseph Snow, Stacey Solin, Barbara J. Stussman, Giorgio Trinchieri, Sara A. Turner, C. Stephenie Vetter, Felipe Vial, Carlotta Vizioli, Ashley Williams, Shanna B. Yang, Avindra Nath

Student Papers, Posters & Projects

Post-infectious myalgic encephalomyelitis/chronic fatigue syndrome (PI-ME/CFS) is a disabling disorder, yet the clinical phenotype is poorly defined, the pathophysiology is unknown, and no disease-modifying treatments are available. We used rigorous criteria to recruit PI-ME/CFS participants with matched controls to conduct deep phenotyping. Among the many physical and cognitive complaints, one defining feature of PI-ME/CFS was an alteration of effort preference, rather than physical or central fatigue, due to dysfunction of integrative brain regions potentially associated with central catechol pathway dysregulation, with consequences on autonomic functioning and physical conditioning. Immune profiling suggested chronic antigenic stimulation with increase in naïve and decrease …

Deficient Histone H3 Propionylation By Brpf1-Kat6 Complexes In Neurodevelopmental Disorders And Cancer., Kezhi Yan, Justine Rousseau, Keren Machol, Laura A. Cross, Katherine E. Agre, Cynthia Forster Gibson, Anne Goverde, Kendra Engleman, Hannah Verdin, Elfride De Baere, Lorraine Potocki, Dihong Zhou, Maxime Cadieux-Dion, Gary A. Bellus, Monisa D. Wagner, Rebecca J. Hale, Natacha Esber, Alan F. Riley, Benjamin D. Solomon, Megan T. Cho, Kirsty Mcwalter, Roy Eyal, Meagan K. Hainlen, Bryce A. Mendelsohn, Hillary M. Porter, Brendan C. Lanpher, Andrea M. Lewis, Juliann Savatt, Isabelle Thiffault, Bert Callewaert, Philippe M. Campeau, Xiang-Jiao Yang

Manuscripts, Articles, Book Chapters and Other Papers

Lysine acetyltransferase 6A (KAT6A) and its paralog KAT6B form stoichiometric complexes with bromodomain- and PHD finger-containing protein 1 (BRPF1) for acetylation of histone H3 at lysine 23 (H3K23). We report that these complexes also catalyze H3K23 propionylation in vitro and in vivo. Immunofluorescence microscopy and ATAC-See revealed the association of this modification with active chromatin. Brpf1 deletion obliterates the acylation in mouse embryos and fibroblasts. Moreover, we identify BRPF1 variants in 12 previously unidentified cases of syndromic intellectual disability and demonstrate that these cases and known BRPF1 variants impair H3K23 propionylation. Cardiac anomalies are present in a subset of the …

New Insights Into Dna Methylation Signatures: Smarca2 Variants In Nicolaides-Baraitser Syndrome., Eric Chater-Diehl, Resham Ejaz, Cheryl Cytrynbaum, Michelle T. Siu, Andrei Turinsky, Sanaa Choufani, Sarah J. Goodman, Omar Abdul-Rahman, Melanie Bedford, Naghmeh Dorrani, Kendra Engleman, Josue Flores-Daboub, David Genevieve, Roberto Mendoza-Londono, Wendy Meschino, Laurence Perrin, Nicole Safina, Sharron Townshend, Stephen W. Scherer, Evdokia Anagnostou, Amelie Piton, Matthew Deardorff, Michael Brudno, David Chitayat, Rosanna Weksberg

Manuscripts, Articles, Book Chapters and Other Papers

BACKGROUND: Nicolaides-Baraitser syndrome (NCBRS) is a neurodevelopmental disorder caused by pathogenic sequence variants in SMARCA2 which encodes the catalytic component of the chromatin remodeling BAF complex. Pathogenic variants in genes that encode epigenetic regulators have been associated with genome-wide changes in DNA methylation (DNAm) in affected individuals termed DNAm signatures.

METHODS: Genome-wide DNAm was assessed in whole-blood samples from the individuals with pathogenic SMARCA2 variants and NCBRS diagnosis (n = 8) compared to neurotypical controls (n = 23) using the Illumina MethylationEPIC array. Differential methylated CpGs between groups (DNAm signature) were identified and used to generate a model enabling classification …

Splice-Altering Variant In Col11a1 As A Cause Of Nonsyndromic Hearing Loss Dfna37., Kevin T. Booth, James W. Askew, Zohreh Talebizadeh, Patrick L M Huygen, James Eudy, Judith Kenyon, Denise Hoover, Michael S. Hildebrand, Katherine R. Smith, Melanie Bahlo, William J. Kimberling, Richard J H Smith, Hela Azaiez, Shelley D. Smith

Manuscripts, Articles, Book Chapters and Other Papers

PURPOSE: The aim of this study was to determine the genetic cause of autosomal dominant nonsyndromic hearing loss segregating in a multigenerational family.

METHODS: Clinical examination, genome-wide linkage analysis, and exome sequencing were carried out on the family.

RESULTS: Affected individuals presented with early-onset progressive mild hearing impairment with a fairly flat, gently downsloping or U-shaped audiogram configuration. Detailed clinical examination excluded any additional symptoms. Linkage analysis detected an interval on chromosome 1p21 with a logarithm of the odds (LOD) score of 8.29: designated locus DFNA37. Exome sequencing identified a novel canonical acceptor splice-site variant c.652-2A>C in the COL11A1 …

Clinical Genome Sequencing In An Unbiased Pediatric Cohort., Isabelle Thiffault, Emily G. Farrow, Lee Zellmer, Courtney D. Berrios, Neil Miller, Margaret Gibson, Raymond Caylor, Janda L. Jenkins, Deb Faller, Sarah E. Soden, Carol J. Saunders

Manuscripts, Articles, Book Chapters and Other Papers

PURPOSE: We report for the first time, the use of clinical genome sequencing (GS) in an unbiased pediatric cohort. We describe the clinical validation, patient metrics, ordering patterns, results, reimbursement, and physician retrieval of results for the first consecutive 80 cases.

METHODS: Clinical GS was performed for both inpatients and outpatients undergoing etiologic evaluations. Results were reported in the electronic medical record. Evidence of report retrieval by clinicians and whether interpretation was concordant with laboratory report was obtained through retrospective chart review.

RESULTS: Twenty definitive diagnoses were made in 19 patients (24%; n = 80). Except for two partial gene …

On The Verge Of Diagnosis: Detection, Reporting, And Investigation Of De Novo Variants In Novel Genes Identified By Clinical Sequencing., Isabelle Thiffault, Maxime Cadieux-Dion, Emily G. Farrow, Raymond Caylor, Neil A. Miller, Sarah E. Soden, Carol J. Saunders

Manuscripts, Articles, Book Chapters and Other Papers

The variable evidence supporting gene-disease associations contributes to the difficulty of accurate variant reporting in a clinical setting. An evidence-based scoring system for evaluating the clinical validity of gene-disease associations, proposed by ClinGen, considers experimental as well as genetic evidence. De novo variants are heavily weighted, given the overall rarity in the genome and their contribution to human disease, however they are reported as "genes of unknown significance" in our center when there is insufficient evidence for the gene-disease assertion. We report a collection of 21 de novo variants in genes of unknown clinical significance ascertained via clinical testing, of …

Prediction Of Cyp2d6 Phenotype From Genotype Across World Populations., Andrea Gaedigk, Katrin Sangkuhl, Michelle Whirl-Carrillo, Teri Klein, J Steven Leeder

Manuscripts, Articles, Book Chapters and Other Papers

PURPOSE: Owing to its highly polymorphic nature and major contribution to the metabolism and bioactivation of numerous clinically used drugs, CYP2D6 is one of the most extensively studied drug-metabolizing enzymes and pharmacogenes. CYP2D6 alleles confer no, decreased, normal, or increased activity and cause a wide range of activity among individuals and between populations. However, there is no standard approach to translate diplotypes into predicted phenotype.

METHODS: We exploited CYP2D6 allele-frequency data that have been compiled for Clinical Pharmacogenetics Implementation Consortium (CPIC) guidelines (>60,000 subjects, 173 reports) in order to estimate genotype-predicted phenotype status across major world populations based on …

Functional Validation Of Novel Compound Heterozygous Variants In B3gat3 Resulting In Severe Osteopenia And Fractures: Expanding The Disease Phenotype., Florian Job, Shuji Mizumoto, Laurie Smith, Natario Couser, Ashley Brazil, Howard Saal, Melanie Patterson, Margaret Gibson, Sarah E. Soden, Neil A. Miller, Isabelle Thiffault, Carol J. Saunders, Shuhei Yamada, Katrin Hoffmann, Kazuyuki Sugahara, Emily G. Farrow

Manuscripts, Articles, Book Chapters and Other Papers

BACKGROUND: A new disease class of syndromes, described as linkeropathies, which are derived from defects in the glycosaminoglycan-linker region as well as glycosaminoglycan-side chains of proteoglycans is increasingly being recognized as a cause of human disease. Proteoglycans are an essential component of the extracellular matrix. Defects in the enzymatic process of proteoglycan synthesis broadly occur due to the incorrect addition of side chains. Previously, homozygous missense variants within the B3GAT3 gene encoding beta 1,3 glucuronyltransferase 3(GlcAT-I) responsible for the biosynthesis of glycosaminoglycans have been described in 7 individuals.

CASE PRESENTATION: In this study, a 4-year-old patient with a severe phenotype …

Constellation: A Tool For Rapid, Automated Phenotype Assignment Of A Highly Polymorphic Pharmacogene,, Greyson P. Twist, Andrea Gaedigk, Neil A. Miller, Emily G. Farrow, Laurel K. Willig, Darrell L. Dinwiddie, Josh E. Petrikin, Sarah E. Soden, Suzanne Herd, Margaret Gibson, Julie A. Cakici, Amanda K. Riffel, J Steven Leeder, Deendayal Dinakarpandian, Stephen F. Kingsmore

Manuscripts, Articles, Book Chapters and Other Papers

An important component of precision medicine-the use of whole-genome sequencing (WGS) to guide lifelong healthcare-is electronic decision support to inform drug choice and dosing. To achieve this, automated identification of genetic variation in genes involved in drug absorption, distribution, metabolism, excretion and response (ADMER) is required. CYP2D6 is a major enzyme for drug bioactivation and elimination. CYP2D6 activity is predominantly governed by genetic variation; however, it is technically arduous to haplotype. Not only is the nucleotide sequence of CYP2D6 highly polymorphic, but the locus also features diverse structural variations, including gene deletion, duplication, multiplication events and rearrangements with the nonfunctional, …

Predicting Targeted Drug Combinations Based On Pareto Optimal Patterns Of Coexpression Network Connectivity, Nadia M. Penrod, Casey S. Greene, Jason H. Moore

Dartmouth Scholarship

Molecularly targeted drugs promise a safer and more effective treatment modality than conventional chemotherapy for cancer patients. However, tumors are dynamic systems that readily adapt to these agents activating alternative survival pathways as they evolve resistant phenotypes. Combination therapies can overcome resistance but finding the optimal combinations efficiently presents a formidable challenge. Here we introduce a new paradigm for the design of combination therapy treatment strategies that exploits the tumor adaptive process to identify context-dependent essential genes as druggable targets. We have developed a framework to mine high-throughput transcriptomic data, based on differential coexpression and Pareto optimization, to investigate drug-induced …

Distinct Phenotypes In Zebrafish Models Of Human Startle Disease, Lisa R. Ganser, Qing Yan, Victoria M. James, Robert Kozol, Maya Topf, Robert J. Harvey, Julia E. Dallman

Faculty Articles

Startle disease is an inherited neurological disorder that causes affected individuals to suffer noise- or touch-induced non-epileptic seizures, excessive muscle stiffness and neonatal apnea episodes. Mutations known to cause startle disease have been identified in glycine receptor subunit (GLRA1 and GLRB) and glycine transporter (SLC6A5) genes, which serve essential functions at glycinergic synapses. Despite the significant successes in identifying startle disease mutations, many idiopathic cases remain unresolved. Exome sequencing in these individuals will identify new candidate genes. To validate these candidate disease genes, zebrafish is an ideal choice due to rapid knockdown strategies, accessible embryonic stages, and stereotyped behaviors. The …

De Novo Frameshift Mutation In Asxl3 In A Patient With Global Developmental Delay, Microcephaly, And Craniofacial Anomalies., Darrell L. Dinwiddie, Sarah E. Soden, Carol J. Saunders, Neil A. Miller, Emily G. Farrow, Laurie D. Smith, Stephen F. Kingsmore

Manuscripts, Articles, Book Chapters and Other Papers

BACKGROUND: Currently, diagnosis of affected individuals with rare genetic disorders can be lengthy and costly, resulting in a diagnostic odyssey and in many patients a definitive molecular diagnosis is never achieved despite extensive clinical investigation. The recent advent and use of genomic medicine has resulted in a paradigm shift in the clinical molecular genetics of rare diseases and has provided insight into the causes of numerous rare genetic conditions. In particular, whole exome and genome sequencing of families has been particularly useful in discovering de novo germline mutations as the cause of both rare diseases and complex disorders.

CASE PRESENTATION: …

Buffered Memory: A Hypothesis For The Maintenance Of Functional, Virus-Specific Cd8(+) T Cells During Cytomegalovirus Infection., Christopher M Snyder

Department of Microbiology and Immunology Faculty Papers

Chronic infections have been a major topic of investigation in recent years, but the mechanisms that dictate whether or not a pathogen is successfully controlled are incompletely understood. Cytomegalovirus (CMV) is a herpesvirus that establishes a persistent infection in the majority of people in the world. Like other herpesviruses, CMV is well controlled by an effective immune response and induces little, if any, pathology in healthy individuals. However, controlling CMV requires continuous immune surveillance, and thus, CMV is a significant cause of morbidity and death in immune-compromised individuals. T cells in particular play an important role in controlling CMV and …

Sustained Cd8+ T Cell Memory Inflation After Infection With A Single-Cycle Cytomegalovirus., Christopher M Snyder, Kathy S Cho, Elizabeth L Bonnett, Jane E Allan, Ann B Hill

Department of Microbiology and Immunology Faculty Papers

Cytomegalovirus (CMV) is a β-herpesvirus that establishes a lifelong latent or persistent infection. A hallmark of chronic CMV infection is the lifelong persistence of large numbers of virus-specific CD8+ effector/effector memory T cells, a phenomenon called "memory inflation". How the virus continuously stimulates these T cells without being eradicated remains an enigma. The prevailing view is that CMV establishes a low grade "smoldering" infection characterized by tiny bursts of productive infection which are rapidly extinguished, leaving no detectable virus but replenishing the latent pool and leaving the immune system in a highly charged state. However, since abortive reactivation with limited …

Comparison Of Human Memory Cd8 T Cell Responses To Adenoviral Early And Late Proteins In Peripheral Blood And Lymphoid Tissue., Amita Joshi, Biwei Zhao, Cara Romanowski, David Rosen, Phyllis Flomenberg

Department of Microbiology and Immunology Faculty Papers

Treatment of invasive adenovirus (Ad) disease in hematopoietic stem cell transplant (SCT) recipients with capsid protein hexon-specific donor T cells is under investigation. We propose that cytotoxic T cells (CTLs) targeted to the late protein hexon may be inefficient in vivo because the early Ad protein E3-19K downregulates HLA class I antigens in infected cells. In this study, CD8+ T cells targeted to highly conserved HLA A2-restricted epitopes from the early regulatory protein DNA polymerase (P-977) and late protein hexon (H-892) were compared in peripheral blood (PB) and tonsils of naturally infected adults. In tonsils, epitope-specific pentamers detected a significantly …

Defining The Phenotypes Of Sickle Cell Disease., Samir K. Ballas

Department of Medicine Faculty Papers

The sickle cell gene is pleiotropic in nature. Although it is a single gene mutation, it has multiple phenotypic expressions that constitute the complications of sickle cell disease. The frequency and severity of these complications vary considerably both latitudinally in patients and longitudinally in the same patient over time. Thus, complications that occur in childhood may disappear, persist or get worse with age. Dactylitis and stroke, for example, occur mostly in childhood, whereas leg ulcers and renal failure typically occur in adults. It is essential that the phenotypic manifestations of sickle cell disease be defined accurately so that communication among …

Definitions Of The Phenotypic Manifestations Of Sickle Cell Disease., Samir K Ballas, Susan Lieff, Lennette J Benjamin, Carlton D Dampier, Matthew M Heeney, Carolyn Hoppe, Cage S Johnson, Zora R Rogers, Kim Smith-Whitley, Winfred C Wang, Marilyn J Telen

Department of Medicine Faculty Papers

Sickle cell disease (SCD) is a pleiotropic genetic disorder of hemoglobin that has profound multiorgan effects. The low prevalence of SCD ( approximately 100,000/US) has limited progress in clinical, basic, and translational research. Lack of a large, readily accessible population for clinical studies has contributed to the absence of standard definitions and diagnostic criteria for the numerous complications of SCD and inadequate understanding of SCD pathophysiology. In 2005, the Comprehensive Sickle Cell Centers initiated a project to establish consensus definitions of the most frequently occurring complications. A group of clinicians and scientists with extensive expertise in research and treatment of …

The Cytoplasmic Tail Of The Rabies Virus G Protein Is An Essential Domain Controlling Death/Survival In Human Neuronal Cells, Christophe Prehaud, Mireille Lafage, Gene S. Tan, Françoise Mégret, Pauline Ménager, Matthias Schnell, Henri Buc, Monique Lafon

Department of Microbiology and Immunology Faculty Papers

Poster presentation.

P53 Activation By Knockdown Technologies, Mara E. Robu, Jon D. Larson, Aidas Nasevicius, Soraya Beiraghi, Charles Brenner

Dartmouth Scholarship

Morpholino phosphorodiamidate antisense oligonucleotides (MOs) and short interfering RNAs (siRNAs) are commonly used platforms to study gene function by sequence-specific knockdown. Both technologies, however, can elicit undesirable off-target effects. We have used several model genes to study these effects in detail in the zebrafish, Danio rerio. Using the zebrafish embryo as a template, correct and mistargeting effects are readily discernible through direct comparison of MO-injected animals with well-studied mutants. We show here indistinguishable off-targeting effects for both maternal and zygotic mRNAs and for both translational and splice-site targeting MOs. The major off-targeting effect is mediated through p53 activation, as detected …

An Intramolecular Association Between Two Domains Of The Protein Kinase Fused Is Necessary For Hedgehog Signaling, Manuel Ascano Jr., David J. Robbins

Dartmouth Scholarship

The protein kinase Fused (Fu) is an integral member of the Hedgehog (Hh) signaling pathway. Although genetic studies demonstrate that Fu is required for the regulation of the Hh pathway, the mechanistic role that it plays remains largely unknown. Given our difficulty in developing an in vitro kinase assay for Fu, we reasoned that the catalytic activity of Fu might be highly regulated. Several mechanisms are known to regulate protein kinases, including self-association in either an intra- or an intermolecular fashion. Here, we provide evidence that Hh regulates Fu through intramolecular association between its kinase domain (ΔFu) and its carboxyl-terminal …

Sart, A Repressor Of Α-Hemolysin In Staphylococcus Aureus, Katherine A. Schmidt, Adhar C. Manna, Steven Gill, Ambrose L. Cheung

Dartmouth Scholarship

In searching the Staphylococcus aureus genome, we found several homologs to SarA. One of these genes, sarT, codes for a basic protein with 118 residues and a predicted molecular size of 16,096 Da. Northern blot analysis revealed that the expression of sarT was repressed by sarA and agr. An insertion sarT mutant generated in S. aureus RN6390 and 8325-4 backgrounds revealed minimal effect on the expression of sarR and sarA. The RNAIII level was notably increased in the sarT mutant, particularly in postexponential-phase cells, while the augmentative effect on RNAII was less. SarT repressed the expression of alpha-hemolysin, as determined …