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Hamvas A, Chaudhari BP, Nogee LM. Genetic testing for diffuse lung diseases in children. Pediatr Pulmonol 2024; 59:2286-2297. [PMID: 37191361 DOI: 10.1002/ppul.26447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 04/04/2023] [Accepted: 04/23/2023] [Indexed: 05/17/2023]
Abstract
Newly developing genomic technologies are an increasingly important part of clinical care and thus, it is not only important to understand the technologies and their limitations, but to also interpret the findings in an actionable fashion. Clinical geneticists and genetic counselors are now an integral part of the clinical team and are able to bridge the complexities of this rapidly changing science between the bedside clinicians and patients. This manuscript reviews the terminology, the current technology, some of the known genetic disorders that result in lung disease, and indications for genetic testing with associated caveats. Because this field is evolving quickly, we also provide links to websites that provide continuously updated information important for integrating genomic technology results into clinical decision-making.
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Affiliation(s)
- Aaron Hamvas
- Department of Pediatrics, Division of Neonatology, Ann and Robert H. Lurie Children's Hospital of Chicago and Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Bimal P Chaudhari
- Divisions of Genetics and Genomic Medicine, Neonatology, Nationwide Children's Hospital, The Ohio State University College of Medicine, Columbus, Ohio, USA
| | - Lawrence M Nogee
- Department of Pediatrics, Eudowood Neonatal Pulmonary Division, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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2
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Casey A, Fiorino EK, Wambach J. Innovations in Childhood Interstitial and Diffuse Lung Disease. Clin Chest Med 2024; 45:695-715. [PMID: 39069332 DOI: 10.1016/j.ccm.2024.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/30/2024]
Abstract
Children's interstitial and diffuse lung diseases (chILDs) are a heterogenous and diverse group of lung disorders presenting during childhood. Infants and children with chILD disorders present with respiratory signs and symptoms as well as diffuse lung imaging abnormalities. ChILD disorders are associated with significant health care resource utilization and high morbidity and mortality. The care of patients with chILD has been improved through multidisciplinary care, multicenter collaboration, and the establishment of patient research networks in the United Stated and abroad. This review details past and current innovations in the diagnosis and clinical care of children with chILD.
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Affiliation(s)
- Alicia Casey
- Department of Pediatrics, Division of Pulmonary Medicine, Harvard Medical School, Boston Children's Hospital, Boston, MA 02115, USA.
| | - Elizabeth K Fiorino
- Department of Science Education and Pediatrics, Donald and Barabara Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY 11549, USA
| | - Jennifer Wambach
- Edward Mallinckrodt Department of Pediatrics, Washington University School of Medicine, St. Louis Children's Hospital, St. Louis, MO 63110, USA
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3
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Wambach JA, Vece TJ. Clinical and research innovations in childhood interstitial lung disease (chILD). Pediatr Pulmonol 2024; 59:2233-2235. [PMID: 38651871 PMCID: PMC11324416 DOI: 10.1002/ppul.27025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Accepted: 04/12/2024] [Indexed: 04/25/2024]
Affiliation(s)
- Jennifer A Wambach
- Edward Mallinckrodt Department of Pediatrics, Washington University School of Medicine, St. Louis Children's Hospital, Saint Louis, Missouri, USA
| | - Timothy J Vece
- Department of Pediatrics, University of North Carolina-Chapel Hill, Chapel Hill, USA
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4
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Griese M, Kurland G, Cidon M, Deterding RR, Epaud R, Nathan N, Schwerk N, Warburton D, Weinman JP, Young LR, Deutsch GH. Pulmonary fibrosis may begin in infancy: from childhood to adult interstitial lung disease. Thorax 2024:thorax-2024-221772. [PMID: 39153860 DOI: 10.1136/thorax-2024-221772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Accepted: 06/25/2024] [Indexed: 08/19/2024]
Abstract
BACKGROUND Childhood interstitial lung disease (chILD) encompasses a group of rare heterogeneous respiratory conditions associated with significant morbidity and mortality. Reports suggest that many patients diagnosed with chILD continue to have potentially progressive or fibrosing disease into adulthood. Over the last decade, the spectrum of conditions within chILD has widened substantially, with the discovery of novel entities through advanced genetic testing. However, most evidence is often limited to small case series, with reports disseminated across an array of subspecialty, clinical and molecular journals. In particular, the frequency, management and outcome of paediatric pulmonary fibrosis is not well characterised, unlike in adults, where clear diagnosis and treatment guidelines are available. METHODS AND RESULTS This review assesses the current understanding of pulmonary fibrosis in chILD. Based on registry data, we have provisionally estimated the occurrence of fibrosis in various manifestations of chILD, with 47 different potentially fibrotic chILD entities identified. Published evidence for fibrosis in the spectrum of chILD entities is assessed, and current and future issues in management of pulmonary fibrosis in childhood, continuing into adulthood, are considered. CONCLUSIONS There is a need for improved knowledge of chILD among pulmonologists to optimise the transition of care from paediatric to adult facilities. Updated evidence-based guidelines are needed that incorporate recommendations for the diagnosis and management of immune-mediated disorders, as well as chILD in older children approaching adulthood.
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Affiliation(s)
- Matthias Griese
- German Center for Lung Research (DZL), University of Munich, LMU Hospital Department of Pediatrics at Dr von Hauner Children's Hospital, Munchen, Germany
| | - Geoffrey Kurland
- Division of Pediatric Pulmonology, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, Pennsylvania, USA
| | - Michal Cidon
- Children's Hospital Los Angeles, Keck School of Medicine of USC, Los Angeles, California, USA
| | - Robin R Deterding
- Section of Pediatric Pulmonary and Sleep Medicine Department of Pediatrics, University of Colorado Denver, Denver, Colorado, USA
- Children's Hospital Colorado, Aurora, Colorado, USA
| | - Ralph Epaud
- Pediatric Pulmonology Department, Centre Hospitalier Intercommunal de Créteil; Centre des Maladies Respiratoires Rares (RESPIRARE®); University Paris Est Créteil, INSERM, IMRB, Créteil, France
| | - Nadia Nathan
- Paediatric Pulmonology Department and Reference Centre for Rare Lung Diseases RespiRare, Laboratory of Childhood Genetic Diseases, Inserm UMS_S933, Sorbonne Université and AP-HP, Hôpital Trousseau, Paris, France
| | - Nicolaus Schwerk
- Clinic for Paediatric Pneumology, Allergy and Neonatology, Hannover Medical School, German Center for Lung Research (DZL), Hannover, Germany
| | - David Warburton
- Children's Hospital Los Angeles, Keck School of Medicine of USC, Los Angeles, California, USA
| | - Jason P Weinman
- Department of Radiology, Children's Hospital Colorado, Aurora, Colorado, USA
| | - Lisa R Young
- Division of Pulmonary and Sleep Medicine, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Gail H Deutsch
- Department of Pathology, Seattle Children's Hospital and University of Washington Medical Center, Seattle, Washington, USA
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Soul J, Carlsson E, Hofmann SR, Russ S, Hawkes J, Schulze F, Sergon M, Pablik J, Abraham S, Hedrich CM. Tissue gene expression profiles and communication networks inform candidate blood biomarker identification in psoriasis and atopic dermatitis. Clin Immunol 2024; 265:110283. [PMID: 38880200 DOI: 10.1016/j.clim.2024.110283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2024] [Revised: 05/24/2024] [Accepted: 06/10/2024] [Indexed: 06/18/2024]
Abstract
Overlapping clinical and pathomechanistic features can complicate the diagnosis and treatment of inflammatory skin diseases, including psoriasis and atopic dermatitis (AD). Spatial transcriptomics allows the identification of disease- and cell-specific molecular signatures that may advance biomarker development and future treatments. This study identified transcriptional signatures in keratinocytes and sub-basal CD4+ and CD8+ T lymphocytes from patients with psoriasis and AD. In silico prediction of ligand:receptor interactions delivered key signalling pathways (interferon, effector T cells, stroma cell and matrix biology, neuronal development, etc.). Targeted validation of selected transcripts, including CCL22, RELB, and JUND, in peripheral blood T cells suggests the chosen approach as a promising tool also in other inflammatory diseases. Psoriasis and AD are characterized by transcriptional dysregulation in T cells and keratinocytes that may be targeted therapeutically. Spatial transcriptomics is a valuable tool in the search for molecular signatures that can be used as biomarkers and/or therapeutic targets.
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Affiliation(s)
- J Soul
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - E Carlsson
- Department of Women's & Children's Health, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom
| | - S R Hofmann
- Department of Pediatrics, Universitätsklinikum Carl Gustav Carus, TU Dresden, Dresden, Germany
| | - S Russ
- Department of Pediatrics, Universitätsklinikum Carl Gustav Carus, TU Dresden, Dresden, Germany
| | - J Hawkes
- Department of Women's & Children's Health, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom
| | - F Schulze
- Department of Pediatrics, Universitätsklinikum Carl Gustav Carus, TU Dresden, Dresden, Germany
| | - M Sergon
- Institut of Pathology, Universitätsklinikum Carl Gustav Carus, TU Dresden, Dresden, Germany
| | - J Pablik
- Institut of Pathology, Universitätsklinikum Carl Gustav Carus, TU Dresden, Dresden, Germany
| | - S Abraham
- Department of Dermatology, Universitätsklinikum Carl Gustav Carus, TU Dresden, Dresden, Germany
| | - C M Hedrich
- Department of Women's & Children's Health, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom; Department of Paediatric Rheumatology, Alder Hey Children's NHS Foundation Trust Hospital, Liverpool, United Kingdom.
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Danhaive O, Galambos C, Lakshminrusimha S, Abman SH. Pulmonary Hypertension in Developmental Lung Diseases. Clin Perinatol 2024; 51:217-235. [PMID: 38325943 DOI: 10.1016/j.clp.2023.12.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
Diverse genetic developmental lung diseases can present in the neonatal period with hypoxemic respiratory failure, often associated with with pulmonary hypertension. Intractable hypoxemia and lack of sustained response to medical management should increase the suspicion of a developmental lung disorder. Genetic diagnosis and lung biopsy are helpful in establishing the diagnosis. Early diagnosis can result in optimizing management and redirecting care if needed. This article reviews normal lung development, various developmental lung disorders that can result from genetic abnormalities at each stage of lung development, their clinical presentation, management, prognosis, and differential diagnoses.
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Affiliation(s)
- Olivier Danhaive
- Division of Neonatology, Saint-Luc University Hospital, UCLouvain, Avenue Hippocrate 10, B-1200 Brussels, Belgium; Department of Pediatrics, University of California San Francisco, 530 Parnassus Avenue, San Francisco, CA 94143, USA.
| | - Csaba Galambos
- Department of Pathology and Laboratory Medicine, University of Colorado Anschutz School of Medicine, 13001 East 17th Place, Aurora, CO 80045, USA
| | - Satyan Lakshminrusimha
- Department of Pediatrics, University of California, UC Davis Children's Hospital, 2516 Stockton Boulevard, Sacramento CA 95817, USA
| | - Steven H Abman
- Department of Pediatrics, The Pediatric Heart Lung Center, University of Colorado Anschutz Medical Campus, Mail Stop B395, 13123 East 16th Avenue, Aurora, CO 80045, USA
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Yamamoto S, Kanca O, Wangler MF, Bellen HJ. Integrating non-mammalian model organisms in the diagnosis of rare genetic diseases in humans. Nat Rev Genet 2024; 25:46-60. [PMID: 37491400 DOI: 10.1038/s41576-023-00633-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/26/2023] [Indexed: 07/27/2023]
Abstract
Next-generation sequencing technology has rapidly accelerated the discovery of genetic variants of interest in individuals with rare diseases. However, showing that these variants are causative of the disease in question is complex and may require functional studies. Use of non-mammalian model organisms - mainly fruitflies (Drosophila melanogaster), nematode worms (Caenorhabditis elegans) and zebrafish (Danio rerio) - enables the rapid and cost-effective assessment of the effects of gene variants, which can then be validated in mammalian model organisms such as mice and in human cells. By probing mechanisms of gene action and identifying interacting genes and proteins in vivo, recent studies in these non-mammalian model organisms have facilitated the diagnosis of numerous genetic diseases and have enabled the screening and identification of therapeutic options for patients. Studies in non-mammalian model organisms have also shown that the biological processes underlying rare diseases can provide insight into more common mechanisms of disease and the biological functions of genes. Here, we discuss the opportunities afforded by non-mammalian model organisms, focusing on flies, worms and fish, and provide examples of their use in the diagnosis of rare genetic diseases.
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Affiliation(s)
- Shinya Yamamoto
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Oguz Kanca
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Michael F Wangler
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA.
| | - Hugo J Bellen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA.
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA.
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Peers de Nieuwburgh M, Wambach JA, Griese M, Danhaive O. Towards personalized therapies for genetic disorders of surfactant dysfunction. Semin Fetal Neonatal Med 2023; 28:101500. [PMID: 38036307 PMCID: PMC10753445 DOI: 10.1016/j.siny.2023.101500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2023]
Abstract
Genetic disorders of surfactant dysfunction are a rare cause of chronic, progressive or refractory respiratory failure in term and preterm infants. This review explores genetic mechanisms underpinning surfactant dysfunction, highlighting specific surfactant-associated genes including SFTPB, SFTPC, ABCA3, and NKX2.1. Pathogenic variants in these genes contribute to a range of clinical presentations and courses, from neonatal hypoxemic respiratory failure to childhood interstitial lung disease and even adult-onset pulmonary fibrosis. This review emphasizes the importance of early recognition, thorough phenotype assessment, and assessment of variant functionality as essential prerequisites for treatments including lung transplantation. We explore emerging treatment options, including personalized pharmacological approaches and gene therapy strategies. In conclusion, this comprehensive review offers valuable insights into the pathogenic mechanisms of genetic disorders of surfactant dysfunction, genetic fundamentals, available and emerging therapeutic options, and underscores the need for further research to develop personalized therapies for affected infants and children.
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Affiliation(s)
- Maureen Peers de Nieuwburgh
- Division of Neonatology, Department of Pediatrics, St-Luc University Hospital, Catholic University of Louvain, Brussels, Belgium.
| | - Jennifer A Wambach
- Washington University School of Medicine/St. Louis Children's Hospital, One Children's Place, St. Louis, Missouri, USA.
| | - Matthias Griese
- Pediatric Pulmonology, Dr von Hauner Children's Hospital, University-Hospital, German Center for Lung Research (DZL), Munich, Germany.
| | - Olivier Danhaive
- Division of Neonatology, Department of Pediatrics, St-Luc University Hospital, Catholic University of Louvain, Brussels, Belgium; Division of Neonatology, Benioff Children's Hospital, University of California San Francisco, San Francisco, CA, USA.
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Marom R, Zhang B, Washington ME, Song IW, Burrage LC, Rossi VC, Berrier AS, Lindsey A, Lesinski J, Nonet ML, Chen J, Baldridge D, Silverman GA, Sutton VR, Rosenfeld JA, Tran AA, Hicks MJ, Murdock DR, Dai H, Weis M, Jhangiani SN, Muzny DM, Gibbs RA, Caswell R, Pottinger C, Cilliers D, Stals K, Eyre D, Krakow D, Schedl T, Pak SC, Lee BH. Dominant negative variants in KIF5B cause osteogenesis imperfecta via down regulation of mTOR signaling. PLoS Genet 2023; 19:e1011005. [PMID: 37934770 PMCID: PMC10656020 DOI: 10.1371/journal.pgen.1011005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 11/17/2023] [Accepted: 10/03/2023] [Indexed: 11/09/2023] Open
Abstract
BACKGROUND Kinesin motor proteins transport intracellular cargo, including mRNA, proteins, and organelles. Pathogenic variants in kinesin-related genes have been implicated in neurodevelopmental disorders and skeletal dysplasias. We identified de novo, heterozygous variants in KIF5B, encoding a kinesin-1 subunit, in four individuals with osteogenesis imperfecta. The variants cluster within the highly conserved kinesin motor domain and are predicted to interfere with nucleotide binding, although the mechanistic consequences on cell signaling and function are unknown. METHODS To understand the in vivo genetic mechanism of KIF5B variants, we modeled the p.Thr87Ile variant that was found in two patients in the C. elegans ortholog, unc-116, at the corresponding position (Thr90Ile) by CRISPR/Cas9 editing and performed functional analysis. Next, we studied the cellular and molecular consequences of the recurrent p.Thr87Ile variant by microscopy, RNA and protein analysis in NIH3T3 cells, primary human fibroblasts and bone biopsy. RESULTS C. elegans heterozygous for the unc-116 Thr90Ile variant displayed abnormal body length and motility phenotypes that were suppressed by additional copies of the wild type allele, consistent with a dominant negative mechanism. Time-lapse imaging of GFP-tagged mitochondria showed defective mitochondria transport in unc-116 Thr90Ile neurons providing strong evidence for disrupted kinesin motor function. Microscopy studies in human cells showed dilated endoplasmic reticulum, multiple intracellular vacuoles, and abnormal distribution of the Golgi complex, supporting an intracellular trafficking defect. RNA sequencing, proteomic analysis, and bone immunohistochemistry demonstrated down regulation of the mTOR signaling pathway that was partially rescued with leucine supplementation in patient cells. CONCLUSION We report dominant negative variants in the KIF5B kinesin motor domain in individuals with osteogenesis imperfecta. This study expands the spectrum of kinesin-related disorders and identifies dysregulated signaling targets for KIF5B in skeletal development.
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Affiliation(s)
- Ronit Marom
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
- Texas Children’s Hospital, Houston, Texas, United States of America
| | - Bo Zhang
- Department of Pediatrics, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - Megan E. Washington
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - I-Wen Song
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Lindsay C. Burrage
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
- Texas Children’s Hospital, Houston, Texas, United States of America
| | - Vittoria C. Rossi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
- Texas Children’s Hospital, Houston, Texas, United States of America
| | - Ava S. Berrier
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Anika Lindsey
- Department of Pediatrics, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - Jacob Lesinski
- Department of Pediatrics, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - Michael L. Nonet
- Department of Neuroscience, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - Jian Chen
- Department of Genetics, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - Dustin Baldridge
- Department of Pediatrics, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - Gary A. Silverman
- Department of Pediatrics, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - V. Reid Sutton
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
- Texas Children’s Hospital, Houston, Texas, United States of America
| | - Jill A. Rosenfeld
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Alyssa A. Tran
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - M. John Hicks
- Texas Children’s Hospital, Houston, Texas, United States of America
- Department of Pathology & Immunology, Baylor College of Medicine, Houston, Texas, United States of America
| | - David R. Murdock
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Hongzheng Dai
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - MaryAnn Weis
- Department of Orthopaedics and Sports Medicine, University of Washington, Seattle, Washington, United States of America
| | - Shalini N. Jhangiani
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Donna M. Muzny
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Richard A. Gibbs
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Richard Caswell
- Exeter Genomics Laboratory, Royal Devon University Healthcare NHS Foundation Trust, Exeter, United Kingdom
| | - Carrie Pottinger
- All Wales Medical Genomics Service, Wrexham Maelor Hospital, Wrexham, UK
| | - Deirdre Cilliers
- Oxford Centre for Genomic Medicine, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | - Karen Stals
- Exeter Genomics Laboratory, Royal Devon University Healthcare NHS Foundation Trust, Exeter, United Kingdom
| | | | - David Eyre
- Department of Orthopaedics and Sports Medicine, University of Washington, Seattle, Washington, United States of America
| | - Deborah Krakow
- Human Genetics, Obstetrics & Gynecology, Orthopedic Surgery, University of California, Los Angeles, California, United States of America
| | - Tim Schedl
- Department of Genetics, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - Stephen C. Pak
- Department of Pediatrics, Washington University School of Medicine, St Louis, Missouri, United States of America
| | - Brendan H. Lee
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
- Texas Children’s Hospital, Houston, Texas, United States of America
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Pulmonary Alveolar Proteinosis and Multiple Infectious Diseases in a Child with Autosomal Recessive Complete IRF8 Deficiency. J Clin Immunol 2022; 42:975-985. [PMID: 35338423 PMCID: PMC8956456 DOI: 10.1007/s10875-022-01250-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Accepted: 03/09/2022] [Indexed: 10/26/2022]
Abstract
BACKGROUND Autosomal recessive (AR) complete IRF8 deficiency is a rare severe inborn error of immunity underlying an absence of blood myeloid mononuclear cells, intracerebral calcifications, and multiple infections. Only three unrelated patients have been reported. MATERIALS AND METHODS We studied an Argentinian child with multiple infectious diseases and severe pulmonary alveolar proteinosis (PAP). We performed whole-exome sequencing (WES) and characterized his condition by genetic, immunological, and clinical means. RESULTS The patient was born and lived in Argentina. He had a history of viral pulmonary diseases, disseminated disease due to bacillus Calmette-Guérin (BCG), PAP, and cerebral calcifications. He died at the age of 10 months from refractory PAP. WES identified two compound heterozygous variants in IRF8: c.55del and p.R111*. In an overexpression system, the p.R111* cDNA was loss-of-expression, whereas the c.55del cDNA yielded a protein with a slightly lower molecular weight than the wild-type protein. The mutagenesis of methionine residues downstream from c.55del revealed a re-initiation of translation. However, both variants were loss-of-function in a luciferase assay, suggesting that the patient had AR complete IRF8 deficiency. The patient had no blood monocytes or dendritic cells, associated with neutrophilia, and normal counts of NK and other lymphoid cell subsets. CONCLUSION We describe the fourth patient with AR complete IRF8 deficiency. This diagnosis should be considered in children with PAP, which is probably due to the defective development or function of alveolar macrophages.
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Fielder SM, Rosenfeld JA, Burrage LC, Emrick L, Lalani S, Attali R, Bembenek JN, Hoang H, Baldridge D, Silverman GA, Schedl T, Pak SC. Functional analysis of a novel de novo variant in PPP5C associated with microcephaly, seizures, and developmental delay. Mol Genet Metab 2022; 136:65-73. [PMID: 35361529 DOI: 10.1016/j.ymgme.2022.03.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 03/13/2022] [Indexed: 11/27/2022]
Abstract
We describe a proband evaluated through the Undiagnosed Diseases Network (UDN) who presented with microcephaly, developmental delay, and refractory epilepsy with a de novo p.Ala47Thr missense variant in the protein phosphatase gene, PPP5C. This gene has not previously been associated with a Mendelian disease, and based on the population database, gnomAD, the gene has a low tolerance for loss-of-function variants (pLI = 1, o/e = 0.07). We functionally evaluated the PPP5C variant in C. elegans by knocking the variant into the orthologous gene, pph-5, at the corresponding residue, Ala48Thr. We employed assays in three different biological processes where pph-5 was known to function through opposing the activity of genes, mec-15 and sep-1. We demonstrated that, in contrast to control animals, the pph-5 Ala48Thr variant suppresses the neurite growth phenotype and the GABA signaling defects of mec-15 mutants, and the embryonic lethality of sep-1 mutants. The Ala48Thr variant did not display dominance and behaved similarly to the reference pph-5 null, indicating that the variant is likely a strong hypomorph or complete loss-of-function. We conclude that pph-5 Ala48Thr is damaging in C. elegans. By extension in the proband, PPP5C p.Ala47Thr is likely damaging, the de novo dominant presentation is consistent with haplo-insufficiency, and the PPP5C variant is likely responsible for one or more of the proband's phenotypes.
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Affiliation(s)
- Sara M Fielder
- Department of Pediatrics, Washington University in St Louis School of Medicine, St Louis, MO 63110, USA
| | - Jill A Rosenfeld
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Lindsay C Burrage
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Texas Children's Hospital, Houston, TX 77030, USA
| | - Lisa Emrick
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Texas Children's Hospital, Houston, TX 77030, USA
| | - Seema Lalani
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Texas Children's Hospital, Houston, TX 77030, USA
| | - Ruben Attali
- Genomic Research Department, Emedgene Technologies, 6744332 Tel Aviv, Israel
| | - Joshua N Bembenek
- Department of Obstetrics and Gynecology, C.S. Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Hieu Hoang
- Department of Pediatrics, Washington University in St Louis School of Medicine, St Louis, MO 63110, USA
| | - Dustin Baldridge
- Department of Pediatrics, Washington University in St Louis School of Medicine, St Louis, MO 63110, USA
| | - Gary A Silverman
- Department of Pediatrics, Washington University in St Louis School of Medicine, St Louis, MO 63110, USA
| | - Tim Schedl
- Department of Genetics, Washington University in St Louis School of Medicine, St Louis, MO 63110, USA
| | - Stephen C Pak
- Department of Pediatrics, Washington University in St Louis School of Medicine, St Louis, MO 63110, USA.
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